Columbia subject headings:
Harvard subject headings:
Anarchism--Spain--Catalonia--History.
Labor unions--Spain--Catalonia--History.
Spain--History--Civil War, 1936-1939.
Princeton subject headings:
Labor unions--Spain--Catalonia--History--20th century.
Labor--Spain--Catalonia--History--20th century.
Spain--History--Civil War, 1936-1939.