Columbia subject headings:
Mexico--Politics and government--1910-1946.
Obregón, Álvaro, 1880-1928.
Harvard subject headings:
Mexico--Politics and government--1910-1946.
Obregón, Álvaro, 1880-1928
Princeton subject headings:
Carranza, Venustiano, 1859-1920.
Obregón, Álvaro, 1880-1928.