Columbia subject headings:
Agricultural laborers--Labor unions--Spain--Córdoba--History.
Catholic labor unions--Spain--Córdoba--History.
Harvard subject headings:
Agricultural laborers--Labor unions--Spain--Córdoba--History.
Catholic labor unions--Spain--Córdoba--History.
Princeton subject headings:
Agricultural laborers--Labor unions--Spain--Córdoba--History.
Catholic labor unions--Spain--Córdoba--History.