Dictionary of the History of Science. Very good source for brief essays on terms, events, in scientific discoveries from 1500 on. War and Peace Ref. A Dictionary of Battles. Essential details of all the major battles in recorded history from Megiddo in 1479 B.C. to Vietnam in the 1960's.
Index includes names of people.
Oxford Companion to World War II . The Dictionary of the First World War Ref. DD 256.5 Encyclopedia of the Third Reich . Translation of first German history of the National Socialist period. Perspectives will differ from those in previous work.