Columbia subject headings:
Partido del Trabajo de España.
Political parties--Spain--History--20th century.
Social movements--Spain--History--20th century.
Spain--Politics and government--20th century.
Harvard subject headings:
Princeton subject headings:
Communism--Spain--History--20th century.
Partido del Trabajo de España--History.
Political parties--Spain--History--20th century.
Social movements--Spain--History--20th century.
Spain--Politics and government--20th century.