Columbia subject headings:
Barcelona (Spain)--History--20th century.
Barcelona (Spain)--Social conditions--20th century.
Harvard subject headings:
Barcelona (Spain)--Social conditions--20th century.
Working class--Spain--Barcelona--Political activity.
Working class--Spain--Barcelona--Social conditions--20th century.
Princeton subject headings:
Barcelona (Spain)--History--20th century.
Barcelona (Spain)--Social conditions--20th century.