Columbia subject headings:
Spain--History--Civil War, 1936-1939--Participation, German.
Harvard subject headings:
Spain--History--Civil War, 1936-1939--Aerial operations, German.
Spain--History--Civil War, 1936-1939--Naval operations, German.
Spain--History--Civil War, 1936-1939--Participation, German.
Princeton subject headings:
Spain--History--Civil War, 1936-1939--Participation, Foreign--German.