Columbia subject headings:
Mexico. Dirección Federal de Seguridad.
Puebla (Mexico : State)--Politics and government--20th century.
Social movements--Mexico--Puebla de Zaragoza--History--20th century.
Student movements--Mexico--Puebla de Zaragoza--History--20th century.
Harvard subject headings:
Princeton subject headings:
Puebla de Zaragoza (Mexico)--History.
Student movements--Mexico--Puebla de Zaragoza--History--20th century.