Columbia subject headings:
Communism--History.
Communist revisionism.
Revolutions and socialism.
Trotsky, Leon, 1879-1940.
Harvard subject headings:
Communism--History--20th century
Communist revisionism.
Revolutions and socialism.
Trotsky, Leon, 1879-1940
Princeton subject headings:
Communism--History--20th century.
Communist revisionism.
Revolutions and socialism.
Trotsky, Leon, 1879-1940.