Columbia subject headings:
Harvard subject headings:
Labor movement--Mexico--Veracruz-Llave (State)--History.
Labor unions--Mexico--Veracruz-Llave (State)--History.
Veracruz-Llave (Mexico : State)--History--20th century.
Veracruz-Llave (Mexico : State)--Social conditions--20th century.
Princeton subject headings:
Labor movement--Mexico--Veracruz-Llave (State)--History.
Labor unions--Mexico--Veracruz-Llave (State)--History.
Veracruz-Llave (Mexico : State)--History--20th century.
Veracruz-Llave (Mexico : State)--Social conditions--20th century.