Columbia subject headings:
Spain--History--Dictatorship, 1923-1930.
Spain--History--Republic, 1931-1939.
Harvard subject headings:
Spain--History--Dictatorship, 1923-1930.
Spain--History--Republic, 1931-1939.
Princeton subject headings:
Spain--History--Dictatorship, 1923-1930.
Spain--History--Republic, 1931-1939.