Columbia subject headings:
Espionage, Spanish.
Germany--Foreign relations--Spain.
Intelligence service--Spain--History--20th century.
Spain--Foreign relations--Germany.
World War, 1939-1945--Secret service--Spain.
Harvard subject headings:
Espionage, Spanish--History--20th century.
Germany--Relations--Spain.
Spain--Relations--Germany.
World War, 1939-1945--Secret service--Spain.
Princeton subject headings: