Columbia subject headings:
Anarchism--Spain--History--20th century.
Confederación Nacional del Trabajo (Spain)--History--20th century.
Labor unions--Political activity--Spain--History--20th century.
Spain--History--Civil War, 1936-1939.
Syndicalism--Spain--History--20th century.
Harvard subject headings:
Anarchism--Spain--History--20th century
Confederación Nacional del Trabajo (Spain)--History--20th century.
Labor unions--Political activity--Spain--History--20th century.
Labor unions--Spain--Political activity--History--20th century.
Spain--History--Civil War, 1936-1939.
Syndicalism--Spain--History--20th century.
Princeton subject headings:
Anarchism--Spain.
Spain--History--Civil War, 1936-1939.