United States 964 History 519 Solid state physics; Properties of matter 268 Education 263 Arts 194 Foreign relations 172 Politics and government 169 Stage Presentation 154 Solid state physics 139 India 127 United states 103 Agriculture 101 State 101 Social Sciences 100 History and criticism 99 Philosophy 97 State, The 96 Social aspects 91 Political science 88 Solid state chemistry 87 Physics 86 Agriculture and state 85 Education and state 81 Management 79 Economics 77 Social conditions 77 Biography 72 Politics 71 Government 69 Political aspects 69