History 218 Land tenure 86 History and criticism 71 Architecture 66 Arquitectura 62 Philosophy 58 Historia 57 more ... urban and land use planning 50 Politics and government 49 General 48 Education 44 Educación 39 Social aspects 38 Social conditions 37 Planificación urbana y uso de las tierras 36 Filosofía 33 Land reform 32 Tenencia de la tierra 32 Land use 31 Law and legislation 31 Law 27 Indians of South America 26 Criticism and interpretation 25 Research 24 Spanish literature 24 Study and teaching 24 Ciencias sociales 23 Economic conditions 21 Medicina 21 Publicaciones periódicas 21 less ...