Columbia subject headings:
Agriculture--Economic aspects--Mexico.
Mexico--Politics and government--20th century.
Peasants--Political activity--Mexico.
Social classes--Mexico.
Harvard subject headings:
Agriculture--Economic aspects--Mexico
Mexico--Politics and government--20th century.
Peasants--Mexico--Political activity.
Social classes--Mexico
Princeton subject headings:
Agriculture--Economic aspects--Mexico.
Mexico--Politics and government--20th century.
Peasants--Mexico--Political activity.
Social classes--Mexico.