Columbia subject headings:
Middle class--Mexico--Tijuana (Baja California)--History--20th century.
Tijuana (Baja California, Mexico)--History--20th century.
Tijuana (Baja California, Mexico)--Intellectual life--20th century.
Harvard subject headings:
Middle class--Mexico--Tijuana (Baja California)--History--20th century.
Tijuana (Baja California, Mexico)--Social conditions--20th century.
Tijuana (Baja California, Mexico)--Social life and customs--20th century.
Princeton subject headings: