Columbia subject headings:
Agricultural laborers--Mexico--History--20th century.
Land tenure--Mexico--History--20th century.
Mexico--Rural conditions.
Peasants--Mexico--History--20th century.
Peasants--Political activity--Mexico--History--20th century.
Harvard subject headings:
Agricultural laborers--Mexico--History--20th century.
Land tenure--Mexico--History--20th century.
Mexico--Rural conditions.
Peasants--Mexico--History--20th century.
Peasants--Mexico--Political activity--History--20th century.
Princeton subject headings:
Agricultural laborers--Mexico--History--20th century.
Land tenure--Mexico--History--20th century.
Peasants--Mexico--History--20th century.
Peasants--Mexico--Political activity--History--20th century.