History 29 Puerto Ricans 27 Social conditions 21 Economic conditions 19 Politics and government 14 Spanish language 12 Congresses 10 Civilization 6 History and criticism 6 Provincialisms 6 Collections 5 Economic policy 5 Education 5 Puerto rican poetry 5 Race relations 5 Commerce 4 Description and travel 4 Harbors 4 Labor supply 4 Spanish American literature 4 Criticism and interpretation 3 Dialects 3 Dictionaries 3 English 3 Folklore 3 Foreign elements 3 Foreign relations 3 Investments, Foreign 3 Minorities 3 National characteristics, Puerto Rican 3