History 52 Biography 39 Politics and government 20 World War, 1939-1945 18 Naval operations 12 Campaigns 8 World War 8 Submarine 5 Civilization 4 Kings and rulers 4 Malaysia 4 Armies 3 Foreign relations 3 Presidents 3 Prime Ministers 3 Social conditions 3 United States 3 World war, 1939-1945 3 Aerial operations, American 2 Atrocities 2 Battles 2 Battleships 2 Case studies 2 Chinese 2 Civilization, Islamic 2 Crusades 2 Description and travel 2 Economic conditions 2 Explorers 2 Government publication 2