History 15 Social aspects 8 Social conditions 8 Computer networks 5 Political aspects 5 Politics and government 5 Data processing 4 Description and travel 4 Exercise 4 Feminism 4 History and criticism 4 Physiological aspects 4 Race relations 4 Sports 4 Sports administration 4 Computer architecture 3 Emigration and immigration 3 Frontier and pioneer life 3 Management 3 Mass media 3 Metals 3 Physical education and training 3 Physical fitness 3 Religious aspects 3 Research 3 African Americans 2 Architecture 2 Athletes 2 Black Arts movement 2 City planning 2