History 17,105 Historia 9,001 General 6,955 Education 6,505 Educación 5,758 Philosophy 5,330 History and criticism 5,323 Politics and government 4,055 Ciencias sociales 3,621 Social aspects 3,532 Filosofía 3,188 Criticism and interpretation 3,137 Law and legislation 2,987 Study and teaching 2,852 Social conditions 2,795 Law 2,783 Research 2,645 Publicaciones periódicas 2,611 Science 2,594 Derecho 2,434 Psicología 2,373 Tecnología 2,285 Periodicals 2,275 Technology 2,267 Medicina 2,146 Social Science 2,056 Psychology 2,043 Economic conditions 2,030 Agricultura 1,907 Public administration 1,899