Columbia subject headings:
Spain--History--Alfonso XIII, 1886-1931--Congresses.
Spain--History--Republic, 1931-1939--Congresses.
Harvard subject headings:
Spain--History--Alfonso XIII, 1886-1931--Congresses.
Spain--History--Republic, 1931-1939--Congresses.
Princeton subject headings:
Spain--History--Alfonso XIII, 1886-1931--Congresses.
Spain--History--Republic, 1931-1939--Congresses.