World War, 1939-1945 27,487 History 7,856 Campaigns 4,993 Regimental histories 1,374 Foreign relations 1,324 Politics and government 1,248 Holocaust, Jewish (1939-1945) 1,213 more ... Jews 1,181 Aerial operations, American 979 Underground movements 853 Diplomatic history 825 Atrocities 766 Naval operations 685 Secret service 609 Prisoners of war 604 Naval operations, American 589 Soldiers 547 Causes 526 History, Military 514 Aerial operations 473 Prisoners and prisons, German 471 Economic aspects 461 World War, 1914-1918 457 Concentration camps 452 Women 443 Prisoners and prisons, Japanese 436 Rescue 411 Peace 392 Submarine 377 Armed Forces 369 less ...