Columbia subject headings:
Harvard subject headings:
Fundación Pablo Iglesias--Archives--Catalogs.
Labor unions--Spain--History--Sources--Bibliography--Catalogs.
Labor unions--Spain--Manuscripts--Catalogs.
Manuscripts, Spanish--Spain--Madrid--Catalogs.
Rosal, Amaro del--Archives--Catalogs.
Socialism--Spain--Sources--Bibliography--Catalogs.
Spain--Politics and government--20th century--Sources--Bibliography--Catalogs.
Unión General de Trabajadores de España--Archives--Catalogs.
Unión General de Trabajadores de España--History--Sources--Bibliography--Catalogs.
Unión General de Trabajadores de Expaña--History--Manuscripts--Catalogs.
Princeton subject headings:
Fundación Pablo Iglesias--Archives--Catalogs.
Fundación Pablo Iglesias. Biblioteca--Catalogs.
Labor unions--Spain--History--Sources--Bibliography--Catalogs.
Rosal, Amaro del--Archives--Catalogs.
Socialism--Spain--History--Sources--Bibliography--Catalogs.
Unión General de Trabajadores de España--Archives--Catalogs.