History 755 World War, 1939-1945 551 Social conditions 348 Social life and customs 284 Social aspects 228 Politics and government 208 Manners and customs 180 more ... Economic conditions 170 Treatment 162 Economic history 141 Operas 132 Environmental aspects 125 Study and teaching 124 Women 118 Excerpts 116 Economic aspects 115 African Americans 114 Psychological aspects 101 Ballet 88 Globalization 86 Civil rights 85 Piano music 85 Exercise 84 Campaigns 83 Military campaigns 83 Dance 80 Music 80 Physical education and training 77 Children 76 Physical fitness 75 less ...