History 140 Land tenure 86 Architecture 61 Arquitectura 58 urban and land use planning 50 Historia 39 Planificación urbana y uso de las tierras 36 more ... History and criticism 33 Politics and government 33 Land reform 32 Tenencia de la tierra 32 Land use 31 Law and legislation 31 Philosophy 27 Education 26 Social aspects 23 Criticism and interpretation 22 Educación 20 Filosofía 18 Social conditions 18 Law 17 Indians of South America 16 Study and teaching 16 Agriculture 14 Derecho 14 Planificación urbana y de uso de las tierras 14 Art 13 Economic conditions 13 Reforma agraria 13 Urbanization 13 less ...