History 175 Land tenure 86 General 65 Architecture 63 History and criticism 63 Arquitectura 59 Historia 56 more ... urban and land use planning 50 Educación 48 Education 45 Philosophy 41 Law and legislation 36 Planificación urbana y uso de las tierras 36 Social conditions 35 Filosofía 32 Land reform 32 Tenencia de la tierra 32 Land use 31 Politics and government 30 Ciencias sociales 28 Medicina 27 Economic conditions 26 Science 25 Spanish literature 25 Agriculture 24 Criticism and interpretation 23 Tecnología 23 Periodicals 22 Publicaciones periódicas 22 Social Science 22 less ...