Columbia subject headings:
Foreign workers, Mexican--West (U.S.)--History.
Labor unions--West (U.S.)--History.
Harvard subject headings:
Foreign workers, Mexican--West (U.S.)--History.
Labor unions--West (U.S.)--History.
Princeton subject headings:
Foreign workers, Mexican--West (U.S.)--History.
Labor unions--West (U.S.)--History.