Columbia subject headings:
South America--History--20th century.
South America--Politics and government--20th century.
Harvard subject headings:
Mexico--History--Revolution, 1910-1920--Influence.
South America--History--20th century.
South America--Politics and government--20th century.
South America--Social conditions--20th century.
Princeton subject headings:
Mexico--History--Revolution, 1910-1920--Influence.
South America--History--20th century.
South America--Politics and government--20th century.
South America--Social conditions--20th century.