Columbia subject headings:
Harvard subject headings:
Working class--Mexico--Political activity--History.
Working class--Political activity--Mexico--History.
Princeton subject headings:
Alemán, Miguel, 1905-1983.
Avila Camacho, Manuel, 1897-1955.
Labor unions--Mexico--History--20th century.
Mexico--Politics and government--1910-1946.
Mexico--Politics and government--1946-1970.
Working class--Mexico--History--20th century.