Columbia subject headings:
Land tenure--Mexico.
Mexico--History--Revolution, 1910-1920--Causes.
Zapata, Emiliano, 1879-1919.
Harvard subject headings:
Mexico--History--Revolution, 1910-1920.
Zapata, Emiliano, 1879-1919
Princeton subject headings:
Mexico--History--Revolution, 1910-1920--Sources.