Columbia subject headings:
Military police--Spain--History--20th century.
Police--Spain--History--20th century.
Police--Spain--History.
Spain--History--Republic, 1931-1939.
Spain. Cuerpo de la Guardia Civil--History.
Harvard subject headings:
Police--Spain--History--20th century.
Spain. Cuerpo de la Guardia Civil--History.
Princeton subject headings: