Columbia subject headings:
Harvard subject headings:
Labor movement--Mexico--History--20th century
Labor movement--United States--History--20th century
Mexico--History--Revolution, 1910-1920.
Mexico--Relations--United States.
Partido Liberal Mexicano--History.
United States--Relations--Mexico.
Princeton subject headings:
Labor movement--Mexico--History--20th century.
Labor movement--United States--History--20th century.
Mexico--History--Revolution, 1910-1920.
Mexico--Relations--United States.
Partido Liberal Mexicano--History.
United States--Relations--Mexico.