Columbia subject headings:
Communists--Mexico.
Cárdenas, Lázaro, 1895-1970.
Mexico--Politics and government--1910-1946.
Political refugees--Mexico.
Trotsky, Leon, 1879-1940.
Harvard subject headings:
Mexico--History--1910-1946
Revolutionaries--Soviet Union--Biography
Statesmen--Soviet Union--Biography
Trotsky, Leon, 1879-1940
Princeton subject headings:
Mexico--History--1910-1946.
Revolutionaries--Soviet Union--Biography.
Statesmen--Soviet Union--Biography.
Trotsky, Leon, 1879-1940.