Columbia subject headings:
Elections--Mexico.
Mexico--Politics and government--1970-1988.
Mexico--Politics and government--1988-2000.
Political parties--Mexico.
Harvard subject headings:
Elections--Mexico
Elections--Mexico--History--20th century.
Elections--Mexico--History--21st century.
Mexico--Politics and government--1970-1988.
Mexico--Politics and government--1988-2000.
Political parties--Mexico
Political parties--Mexico--History--20th century
Political parties--Mexico--History--21st century.
Princeton subject headings:
Elections--Mexico.
Mexico--Politics and government--1970-1988.
Mexico--Politics and government--1988-2000.
Political parties--Mexico.