Columbia subject headings:
Labor unions--Spain--History--20th century.
Unión General de Trabajadores de España--History--20th century.
Harvard subject headings:
Labor unions--Spain--History--20th century.
Spain--Politics and government--1939-1975.
Unión General de Trabajadores de España--History--20th century.
Princeton subject headings:
Labor unions--Spain--History--20th century.
Unión General de Trabajadores de España--History--20th century.