United States 964 History 553 Education 271 Solid state physics; Properties of matter 268 Arts 208 Politics and government 208 Foreign relations 176 Stage Presentation 154 Solid state physics 139 India 129 Philosophy 104 Social aspects 103 United states 103 State 101 History and criticism 100 Agriculture 98 State, The 96 Political science 94 Social Sciences 94 Economics 91 Social conditions 90 Women 90 Solid state chemistry 87 Agriculture and state 85 International relations 84 Political aspects 82 Education and state 81 Law and legislation 80 Law 79 Democracy 74