In this article, I wanna walk you through the World War 2 for UPSC, World History (UPSC Notes).

We have seen the causes and consequences of the First World War in our previous article.

The first world war itself sowed the seeds for Second World War, primarily because of the humiliating Treaty of Versailles. In this article, We shall see the causes and consequences of World War 2 for UPSC (WW – II).

The Second World War: 1939-45

As Germany, Italy, and Japan conquered other countries, the rest of the world did nothing to stop them. By the mid-1930s, Germany and Italy seemed bent on military conquest. The major democracies; Britain, France, and the United States were distracted by economic problems at home and longed to remain at peace. With the world moving toward war, many nations pinned their hopes for peace on the League of Nations. As fascism spread in Europe, a powerful nation in Asia moved toward a similar system. Following a period of reform and progress in the 1920s, Japan fell under military rule.

Some of the major events-

  • Japan invades Manchuria-1931
  • Italy attacks Ethiopia-1935
  • Germany occupies Rhineland- 1936
  • Japan invades China-1937
  • Germany annexes Austria-1938
  • Germany takes Sudetenland-1938
  • Germany seizes Czechoslovakia-1939
  • Italy conquers Albania-1939
World War 2

For the Chinese, the war began in 1931, when Japan invaded northeastern China, setting up a Japanese state called Manchukuo.

By 1938 Japan occupied much of China and had taken Nanking, the longtime capital of China, where Japanese troops killed more than 42,000 civilians.

For Europeans, the war began in 1939, when Germany invaded Poland. The war in Europe ended in May 1945 and in the Pacific in August 1945.

For Americans, World War II began on December 7, 1941.

But war had been going on for years at different places from Europe to Asia.

Germany conquered France. German troops occupied northern and western France. Pro-German French officials set up a capital in Vichy and run the rest of France under Germany’s watchful eye.

Using more than a thousand warships, yachts, fishing boats, and smaller craft at the battered port of Dunkirk, England evacuates more than 338,000 troops from conquered France.

Battle of the Atlantic begins as German submarines, called U-boats, begin sinking ships carrying oil and other war supplies from America to England.

Who are in allies and axis side?

allies and axis side world war 2


In August 1939 Germany, under Hitler, and the Soviet Union, under Stalin, signed the Non-aggression Pact, which secretly accepts Germany’s plan to invade Poland.

The Molotov–Ribbentrop Pact, also known as the Nazi-Soviet Pact, the German-Soviet Non-aggression Pact, or the Nazi German-Soviet Pact of Aggression.

In the Blitzkrieg attack, Germany invaded Poland in a Blitzkrieg (lightning war), the Polish were defeated swiftly due to ill-preparedness to deal with the German aggression.

The Luftwaffe (the German air force) put the Polish railway system out of action and destroyed the Polish air force.

Polish resistance was heroic but hopeless: they had no motorized divisions and they tried to stop advancing German tanks by massed cavalry charges.

England and France reacted by declaring war on Germany. This begins the European War, which will become World War II.

german invasion of poland

The Phoney War:

The Soviet Union invaded Finland, occupied part of Poland, and, by threatening invasion, takes over Lithuania, Estonia, and Latvia.

  • When the Russians invaded eastern Poland, resistance collapsed. On 29 September Poland was divided up between Germany and the USSR (as agreed in the pact of August 1939).
  • The trench warfare of World War I convinced the French that a strong defense would be crucial to stopping a future German invasion.
  • So, France constructed a series of fortifications known as the Maginot Line that stretched along the common border between France and Germany.

Importance of Denmark and German invasion to Germany

Hitler’s troops occupied Denmark and landed at the main Norwegian ports, rudely shattering the apparent calm of the ‘Phoney war’.

  • Control of Norway was important for the Germans because Narvik was the main outlet for Swedish iron-ore, which was vital for the German armaments industry.
  • As the British were interfering with this trade by laying mines in Norwegian coastal waters, and the Germans were afraid that they might try to take over some of Norway’s ports, which they were in fact planning to do.

Why Germany was able to invade Norway and Denmark and what they got in this deal?

  • The Germans were successful because the Norwegians had been taken by surprise and their troops were not even mobilized; local Nazis, under their leader Vidkun Quisling, gave the invaders every assistance.
  • As the British had no air support, whereas the German air force constantly harassed the Allies.
  • Germany was assured of her bases and her iron-ore supplies but had lost three cruisers and ten destroyers. This made the German navy less effective at Dunkirk than it might have been.
  • It showed the incompetence of the Chamberlain’s government. He was forced to resign and Winston Churchill became British prime minister.
  • Although there has been criticism of Churchill’s mistakes, there is no doubt that he supplied what was needed at the time – drive, a sense of urgency, and the ability to make his coalition cabinet work well together.
planned division of central europe 1

Hitler’s attacks on Holland, Belgium and France:

The attacks on Holland, Belgium and France were launched simultaneously, and again Blitzkrieg methods brought swift victories.

The Dutch, shaken by the bombing of Rotterdam, which killed almost a thousand people, surrendered after only four days.

Belgium held out for longer, but her surrender at the end of May left the British and French troops in Belgium perilously exposed as German motorized divisions swept across northern France; only Dunkirk remained in Allied hands.

The British navy played the vital role in evacuating over 338 000 troops two-thirds of them British from Dunkirk between 27 May and 4 June, which was a remarkable achievement in the face of constant Luftwaffe attacks on the beaches.

It would perhaps have been impossible if Hitler had not ordered the German advance towards Dunkirk to halt (24 May), probably because the marshy terrain and numerous canals were unsuitable for tanks.

It was a serious blow for the Allies: the troops at Dunkirk had lost all their arms and equipment, so it became impossible for Britain to help France.

After that Germans swept southwards, Paris was captured on 14 June and France surrendered on 22 June.

Why France was defeated so quickly?

  • The French were psychologically unprepared for war and were bitterly divided between right and left.
  • There were serious military weaknesses; France had to face the full weight of an undivided German offensive, whereas in 1914 half the German forces had been directed against Russia.
  • The French High Command was content to sit behind the Maginot Line, a line of defenses stretching from the Swiss to the Belgian frontiers.
  • Unfortunately, the Maginot Line did not continue along the frontier between France and Belgium, partly because that might have offended the Belgians, and because Petain believed that the Ardennes would be a strong enough barrier; but this was exactly where the Germans broke through.
  • France had as many tanks and armored vehicles as Germany, but instead of being concentrated in completely mechanized armored divisions, allowing greater speed, they were split up so that each infantry division had a few.
  • The German divisions were supported by combat planes, another area neglected by the French.
  • The French generals made fatal mistakes like no attempt was made to help Poland by attacking Germany in the west in September 1939, which might have had a good chance of success.
  • No troops were moved from the Maginot Line forts or most of which were completely inactive to help block the German breakthrough on the River Meuse.
  • There was poor communication between the army and air force so that air defense to drive German bombers off usually failed to arrive.
  • Military defeats gave the defeatist right the chance to come out into the open and put pressure on the government to accept a ceasefire.

The Battle of Britain (12 August to 30 September 1940)

This was fought in the air when Goering’s Luftwaffe tried to destroy the Royal AirForce as a preliminary to the invasion of Britain.

The Germans bombed harbors, radar stations, aerodromes, and munitions factories; in September they began to bomb London, in retaliation, they claimed, for a British raid on Berlin.

The RAF inflicted heavy losses on the Luftwaffe in which 1389 German planes were lost as against 792 British; when it became clear that British air power was far from being destroyed, Hitler called off the invasion.

Reasons for the British success were:

  • Their chain of new radar stations gave plenty of warning of approaching German attackers.
  • The German bombers were poorly armed, though the British fighters were not significantly better than the German Messerschmitt’s, the Germans were hampered by limited range – they could only carry enough fuel to enable them to stay in the air about 90 minutes.
  • The switch to bombing London was a mistake because it relieved pressure on the airfields at the critical moment.

The Battle of Britain was probably the first major turning point of the war: for the first time, the Germans had been checked, demonstrating that they were not invincible.

Mussolini invades Egypt, September 1940:

  • Not wanting to be outdone by Hitler, Mussolini sent an army from the Italian colony of Libya which penetrated about 60 miles into Egypt, while another Italian army invaded Greece from Albania.
  • However, the British soon drove the Italians out of Egypt, pushed them back far into Libya and defeated
  • British naval aircraft sank half the Italian fleet in harbor at Taranto and occupied Crete.
  • The Greeks forced the Italians back and invaded Albania.
  • Mussolini was beginning to be an embarrassment to Hitler.


Hitler’s first moves in 1941 were to help out his faltering ally. In February he sent troops to Tripoli, and together with the Italians, they drove the British out of Libya.

In April 1941 Hitler’s forces invaded Greece, the day after 60,000 British, Australian and New Zealand troops had arrived to help the Greeks.

The Germans soon captured Athens, forcing the British to withdraw, and after bombing Crete, they launched a parachute invasion of the island; again the British were forced to evacuate in May 1941.

world war 2 1941


Hitler’s motives seem to have been mixed, when it comes to invading Russia:

He feared that the Russians might attack Germany while his forces were still occupied in the west and he hoped that the Japanese would attack Russia in the Far East.

The more powerful Japan became, the less chance there was of the USA entering the war.

But above all there was his hatred of communism and his desire for Lebensraum.

The German attack was three-pronged:

  • In the north towards Leningrad,
  • In the center towards Moscow,
  • In the south through the Ukraine.

Stalin’s thoughts on Germans and USA:

  • It was Blitzkrieg on an awesome scale, important cities such as Riga, Smolensk, and Kiev were captured.
  • The Russians had been caught off their guard, in spite of British and American warnings that a German attack was imminent.
  • Stalin apparently believed that Hitler could be trusted to honor the Nazi-Soviet nonaggression pact, and was extremely suspicious of any information which came from Britain or the USA.
  • The Russians were still re-equipping their army and air force, and many of their generals were inexperienced.

German forces failed to capture Leningrad and Moscow:

  • They were severely hampered by the heavy rains of October, which turned the Russian roads into mud, and by the severe frosts of November and December when in some places the temperature fell to minus 38°C.
  • The Germans had inadequate winter clothing because Hitler had expected the campaigns to be over by the autumn.
  • Even in the spring of 1942, no progress was made in the north and center as Hitler decided to concentrate on a major drive south-eastward towards the Caucasus to seize the oilfields.


  • The USA was brought into the war by the Japanese attack on Pearl Harbor, their naval base in the Hawaiian Islands on 7 December 1941.
  • Until then Americans remained neutral, though after the Lend-Lease Act April 1941, they had provided Britain with massive financial aid.
  • Japanese motives for the attack were tied up with her economic problems.
  • The government behaved they would soon ruin shortly of raw materials and cast longing eyes towards territories such as Britain’s Malaya and Burma, which had minerals, oil, and tin, and towards the Dutch Eas1t Indies, also rich in oil.
  • Since both Britain and Holland were in no fit state to defend their possessions, the Japanese prepared to attack, though they would probably have preferred to avoid war with the USA.
  • Relations between the two states deteriorated steadily. The Americans assisted the Chinese, who were still at war with Japan; when the Japanese persuaded Vichy France to allow them to occupy French Indo-China, President Roosevelt demanded their withdrawal and placed an embargo on oil supplies to Japan.
  • Long negotiations followed in which the Japanese tried to persuade the Americans to lift the embargo.

The attack was brilliantly organized by Admiral Yamamoto. There was no declaration of war: 353 Japanese planes arrived undetected at Pearl Harbor, and in two hours, destroyed 350 aircraft and five battleships; 3700 men were killed or seriously injured. Roosevelt called 7 December ‘a date which will live in infamy’.

Pearl Harbor had important results:

It gave the Japanese control of the Pacific, and by May 1942 they had captured Malaya, Singapore, Hong Kong, and Burma all part of the British Empire, the Dutch East Indies, the Philippines, and two American possessions, Guam and Wake Island.

It caused Hitler to declare war on the USA. Declaring war on the USA was perhaps Hitler’s most serious mistake.

He need not at this stage have committed himself to war with the USA, in which case the Americans might well have concentrated on the Pacific war.

However, the Germans had already assured the Japanese that they would come to Japan’s aid if she was ever at war with the USA.

Hitler assumed that President Roosevelt of the USA would declare war on Germany sooner or later, so he wanted to get Germany’s declaration of war in first, to show the German people that he, and not the Americans, controlled events.

world war 2 in the pacific

America’s reaction to Hitler’s declaring war against them:

  • US Congress was naturally determined to have their revenge on Japan but was still reluctant to get involved in Europe.
  • Roosevelt would have had a difficult job to persuade Congress to declare war on Germany; Hitler’s action saved him the trouble.

As it was, Germany was now faced with the immense potential of the USA. This meant that with the vast resources of the USSR and the British Commonwealth as well, the longer the war lasted, the less chance there was of an Axis victory. It was essential for them to deliver swift knock-out blows before the American contribution became effective.

Brutal behavior by Germans and Japanese:

The behavior of both Germans and Japanese in their conquered territories was ruthless and brutal. The Nazis treated the peoples of Eastern Europe as sub-humans, fit only to be slaves of the German master-race. As for the Jews – they were to be exterminated. The Japanese treated their prisoners of war and the Asian peoples badly.


In three separate areas of fighting, Axis forces were defeated and began to lose ground:

  • Midway Island
  • El Alamein
  • Stalingrad

Midway Island, June 1942:

At Midway Island in the Pacific the Americans beat off a powerful Japanese attack, there were several reasons for the American victory against heavier odds:

  • They had broken the Japanese radio code and knew exactly when and where the attack was to be launched.
  • The Japanese were over-confident and made two fatal mistakes: they split their forces, thus allowing the Americans to concentrate on the main carrier force; and they attacked with aircraft from all four carriers simultaneously, so that when they were all rearming, the entire fleet was extremely vulnerable.

Midway proved to be a crucial turning point in the battle for the Pacific: the loss of their carriers and strike planes seriously weakened the Japanese, and from then on the Americans maintained their lead in carriers and aircraft, especially dive-bombers. Although the Japanese had far more battleships and cruisers, they were mostly ineffective: the only way war could be waged successfully in the vast expanses of the Pacific was by air power operating from carriers.

El Alamein, October 1942:

At El Alamein in Egypt Rommel’s Afrika Korps were driven back by the British Eighth Army, commanded by Montgomery. This great battle was the culmination of several engagements fought in the El Alamein area:

  • First, the Axis advance was temporarily checked in July;
  • When Rommel tried to break through, he has halted again at Alam Halfa in September;
  • Finally, seven weeks later in the October battle, he was chased out of Egypt for good by the British and New Zealanders.
  • The Allies were successful partly because during the seven-week pause, massive reinforcements had arrived so that the Germans and Italians were heavily outnumbered.

The El Alamein victory was another turning point in the war:

It prevented Egypt and the Suez Canal from falling into German hands.

  • It ended the possibility of a link-up between the Axis forces in the Middle East and those in Ukraine.
  • More than that, it led to the complete expulsion of Axis forces from North Africa.
  • It encouraged landings of British troops in the French territories of Morocco and Algeria to threaten the Germans and Italians from the west, while the Eighth Army closed in on them from Libya. Trapped in Tunisia, 275 000 Germans and Italians were forced to surrender (May 1943), and the Allies were well-placed for an invasion of Italy.

The desert war had been a serious drain on German resources that could have been used in Russia, where they were badly needed.


  • At Stalingrad the southern prong of the German invasion of Russia, which had penetrated deeply through the Crimea, capturing Rostov-on-Don, was finally checked.
  • The Germans had reached Stalingrad at the end of August 1942, but though they more or less destroyed the city, the Russians refused to surrender.
  • In November they counter-attacked ferociously, trapping the Germans, whose supply lines were dangerously extended, in a large pincer movement.

With his retreat cut off, the German commander, von Paulus, had no reasonable alternative but to surrender with 94 000 men (2 February 1943).

What part was played by allied naval forces?

  • After the initial shock at Pearl Harbor, the Americans were able to build up that superiority in both air and sea departments, which was to lead to the eventual defeat of Japan.
  • At the same time the British navy, as in the First World War, had a vital role to play: this included protecting merchant ships bringing food supplies, sinking German submarines and surface raiders, blockading Germany, and transporting and supplying Allied troops fighting in North Africa and later in Italy.
  • At first, success was mixed, mainly because the British failed to understand the importance of air support in naval operations and had few aircraft carriers. Thus, they suffered defeats in Norway and Crete, where the Germans had strong air superiority.
  • In addition, the Germans had many naval bases in Norway, Denmark, France, and Italy. In spite of this, the British navy could point to some important achievements.

(a) British successes through air and sea power:

  • Aircraft from the carrier Illustrious sank half the Italian fleet at Taranto.
  • The threat from surface raiders was removed by the sinking of the Bismarck, Germany’s only battleship at the time
  • The navy destroyed the German invasion transports on their way to Crete.
  • Their most important contribution was their victory in the Battle of the Atlantic
  • Sea and airpower together made possible the great invasion of France in June 1944.

(b) The Battle of the Atlantic:

This was the struggle against German U-boats attempting to deprive Britain of food and raw materials. The reasons for the Allied success were:

• More air protection was provided for convoys by long-range Liberators;
• Both escorts and aircraft improved with experience;
• The British introduced the new centimetric radar sets, which were small enough to be fitted into aircraft; these enabled submarines to be detected in poor visibility and at night.

The victory was just as important as Midway, El Alamein and Stalingrad: Britain could not have continued to sustain the losses of March 1943 and still remained in the war.

What contribution did air power make to the defeat of the axis?

(a) Achievements of Allied air power:

  • The first significant achievement was in the Battle of Britain, when the RAF beat off the Luftwaffe attacks, causing Hitler to abandon his invasion plans.
  • In conjunction with the British navy, aircraft played a varied role.
  • The American air force together with the navy played a vital part in winning the Pacific War against the Japanese.
  • The RAF took part in specific campaigns that would have been hopeless without them.
  • British and Americans later flew parachute troops in, to aid the landings in Sicily and Normandy, and provided air protection for the invading armies.

(b) Allied bombing of German and Japanese cities:

The most controversial action was the Allied bombing of German and Japanese cities. The Germans had bombed London and other important British cities and ports during 1940 and 1941, but these raids dwindled during the German attack on Russia, which required all the Luftwaffe’s strength. The British and Americans retaliated with what they called a ‘strategic air offensive’ – this involved massive attacks on military and industrial targets in order to hamper the German war effort. The Ruhr, Cologne, Hamburg and Berlin all suffered badly.

Sometimes raids seem to have been carried out to undermine civilian morale, as when about 50 000 people were killed during a single night raid on Dresden.

Some of the arguments that this type of bombing, which caused the deaths of so many innocent civilians, was morally wrong. Estimates of German civilian deaths from Allied bombing vary between 600 000 and a million; German raids on Britain killed over 60 000 civilians. In 2001 Swedish writer Sven Lindquist, in his book A History of Bombing, suggested that what he called ‘the systematic attacks on German civilians in their homes’ should be viewed as ‘crimes under international humanitarian law for the protection of civilians’.

In the end, therefore, after much-wasted effort early on, the Allied strategic air offensive was one of the decisive reasons for the Axis defeat: besides strangling fuel and armaments production and destroying railway communications, it caused the diversion of many aircraft from the eastern front, thus helping the Russian advance into Germany.

Why did the axis powers lose the war?

allied vs axis powers

The reasons can be summarized briefly:

  • Shortage of raw materials- Both Italy and Japan had to import supplies, and even Germany was short of rubber, cotton, nickel, and, after mid-1944, oil.
  • The Allies learning from their mistakes and failures- By 1942 they knew how to check Blitzkrieg attacks and appreciated the importance of air support and aircraft carriers.
  • The Axis powers taking on too much- they became stretched out far beyond their basic capacity for holding their gains. Japan was a small island state with limited industrial power. In Germany’s case, Mussolini was partly to blame: his incompetence was a constant drain on Hitler’s resources.
  • The overwhelming impact of the combined resources of the USA, the USSR and the British Empire;
  • Tactical mistakes by the Axis powers- Nazi treatment of Jews, gypsies, and homosexuals in occupied territories of the USSR alienated many of the conquered peoples who, with decent treatment, could have been brought on board to fight the Stalinist regime.

The Holocaust

As the invading Allied armies moved into Germany and Poland, they began to make horrifying discoveries. At the end of July 1944, Soviet forces approaching Warsaw came upon the extermination camp at Majdanek near Lublin. They found hundreds of unburied corpses and seven gas chambers.

Earlier interpretations of the Holocaust can be divided into two main groups.

  • Internationalists – historians who believed that responsibility for the Holocaust rests on Hitler, who had hoped and planned to exterminate the Jews ever since he came to power.
  • Functionalists – historians who believed that the ‘Final Solution’ was in a sense forced on Hitler by the circumstances of the war.
  • Final solution – Alan Bullock argued that the best way to explain how the Holocaust came about is to combine elements from both intentionalists and functionalists. From the early 1920s, Hitler had committed himself and the Nazi party to destroying the power of the Jews and driving them out of Germany, but exactly how this was to be done was left vague. ‘It is very likely’, writes Bullock, ‘that among the fantasies in which he indulged privately, was the evil dream of a final settlement in which every man, woman, and child of Jewish race would be butchered. But how, when, even whether, the dream could ever be realized remained uncertain.
  • Genocide – As the extermination program gained momentum, the Jews from Eastern Europe were taken to Belzec, Sobibor, Treblinka, and Majdanek in eastern Poland; most of those from Western Europe went to Auschwitz-Birkenau in southwest Poland.

What were the effects of the war?

effects of ww 2

Enormous destruction:

• There was enormous destruction of lives, homes, industries and communications in
Europe and Asia. Almost 40 million people ·were killed: well over half of them were
Russians; 6 million were Poles, 4 million Germans, 2 million Chinese and 2 million
Japanese. Britain and the USA got off comparatively lightly.
• Though the cost was high, it did mean that the world had been rid of Nazism, which
had been responsible for terrible atrocities. The most notorious was the Holocaust – the deliberate murder in extermination camps of over five million Jews and hundreds
of thousands of non-Jews, mainly in Poland and Russia.

ww 2 deaths

There was no all-inclusive peace settlement:

This was different from the end of the First World War when an all-inclusive settlement was
negotiated at Versailles. This was mainly because the distrust which had re-emerged between
the USSR and the west in the final months of the war made an agreement on many points

The war stimulated important social changes:

  • In addition to the population movements during the war, once hostilities were over, many millions of people were forced to move from their homes.
  • The worst cases were probably in the areas taken from Germany by Russia and Poland, and in the German-speaking areas in Hungary, Romania and Czechoslovakia.
  • About ten million Germans were forced to leave and make their way to West Germany so that no future German government would be able to claim those territories.
  • In some countries, especially the USSR and Germany, extensive urban redevelopment took place as ruined cities had to be rebuilt.
  • In Britain, the war stimulated, among other things, the Beveridge Report (1942), a plan for introducing a Welfare State.

The war caused the production of nuclear weapons:

The first-ever use of these weapons, on Hiroshima and Nagasaki, demonstrated their horrifying powers of destruction. The world was left under the threat of a nuclear war that might well have destroyed the entire planet. Some people argue that this acted as a deterrent, making both sides in the Cold War so frightened of the consequences that they were deterred or discouraged from fighting each other.

Europe’s domination of the rest of the world ended:

The four western European states which had played a leading role in world affairs for most of the first half of the twentieth century were now much weaker than before. Germany was devastated and divided; France and Italy were on the verge of bankruptcy; although Britain seemed strong and victorious, with her empire intact, the cost of the war had been ruinous.

Emergence of the superpowers:

  • The USA and the USSR emerged as the two most powerful nations in the world, and they were no longer as isolated as they had been before the war.
  • The USA had suffered relatively little from the war and had enjoyed great prosperity from supplying the other Allies with war materials and food.
  • The Americans had the world’s largest navy and air force and they controlled the atomic bomb.
  • The USSR, though severely weakened, still had the largest army in the world.
  • The rivalry of these two superpowers in the Cold War was the most important feature of international relations for almost half a century after 1945 and was a constant threat to world peace.


  • The war encouraged the movement towards decolonization. The defeats inflicted on Britain, Holland and France by Japan, and the Japanese occupation of their territories.
  • Gradually they achieved full independence, though not without a struggle in many cases.
  • This in turn intensified demands for independence among the peoples of Africa and the Middle East, and in the 1960s the result was a large array of new states.
  • The leaders of many of these newly emerging nations met in conference at Algiers in 1973 and made it clear that they regarded themselves as a Third World.
  • By this, they meant that they wished to remain neutral or non-aligned in the struggle between the other two worlds – communism and capitalism.
  • Usually poor and under-developed industrially, the new nations were often intensely suspicious of the motives of both communism and capitalism, and they resented their own economic dependence on the world’s wealthy powers.

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please tell us the references for this article. what books did you read for this topic?