Columbia subject headings:
Mexico--Politics and government--1946-1970.
Mexico--Politics and government--1970-1988.
Presidents--Mexico.
Harvard subject headings:
Mexico--Politics and government--1946-1970
Mexico--Politics and government--1970-1988.
Princeton subject headings:
Mexico--Politics and government--1946-1970.
Mexico--Politics and government--1970-.
Presidents--Mexico.