Columbia subject headings:
Harvard subject headings:
Spain--History--Civil War, 1936-1939--Causes.
Spain--History--Civil War, 1936-1939--Sources.
Spain--Politics and government--1931-1939.
Princeton subject headings:
Spain--History--Civil War, 1936-1939--Causes.
Spain--History--Civil War, 1936-1939--Sources.
Spain--Politics and government--1931-1939.