History 275 Philosophy 126 Economics 82 History and criticism 78 English literature 75 Politics and government 74 Mathematics 67 Free trade 59 Social conditions 56 Agronomy 46 Agriculture 45 Economic development 43 Women 43 Biography 40 Computer science 39 Intellectual life 39 Data mining 38 Research 38 Social aspects 37 R (Computer program language) 36 Colonies 35 Globalization 34 Management 34 Mass media 33 Free enterprise 31 India 31 Law 31 Rural development 31 Statistics 31 Civilization 30