History 588 Politics and government 375 Foreign relations 282 English language 200 International relations 120 Economic conditions 106 World politics 87 Military policy 77 Dictionaries 75 Armed Forces 74 Study and teaching 72 World War, 1939-1945 70 Biography 69 Social conditions 65 Terrorism 54 Congresses 53 Military art and science 52 Communism 51 War 51 Economic policy 49 Political activity 47 Nationalism 44 Strategy 43 Problems, exercises, etc 42 Case studies 39 Philosophy 36 United States 36 Research 34 Textbooks for foreign speakers 34 Islam 33