Columbia subject headings:
Belligerency.
Diplomacy.
Neutrality.
Spain--Foreign relations--1931-1939.
Spain--History--Civil War, 1936-1939.
War (International law)
Harvard subject headings:
Belligerency.
Diplomacy.
Neutrality.
Spain--Foreign relations.
Spain--History--Civil War, 1936-1939.
War (International law)
Princeton subject headings:
Belligerency.
Diplomacy.
Neutrality.
Spain--Foreign relations--1931-1939.
Spain--History--Civil War, 1936-1939.
War (International law)