History 1,586 Politics and government 476 Social aspects 408 History and criticism 386 Management 315 Data processing 289 Analysis 271 Research 231 Mathematics 230 Philosophy 226 Materials 224 Mathematical models 221 Testing 212 Social conditions 199 Design and construction 183 Enzymes 183 Economic conditions 172 Study and teaching 168 Criticism and interpretation 166 Economic aspects 162 Methodology 153 Addresses, essays, lectures 141 Foreign relations 137 Science 132 Technological innovations 128 Design 127 Information technology 127 Metals 127 Environmental aspects 123 Political aspects 123