Columbia subject headings:
Communism--Soviet Union--History.
Communist parties--Social aspects--Soviet Union.
Communist parties--Soviet Union--History.
Harvard subject headings:
Communism--Soviet Union--History
Communist parties--Social aspects--Soviet Union.
Communist parties--Soviet Union--History.
Princeton subject headings:
Communism--Europe, Eastern--History.
Communism--Soviet Union--History.
Communist parties--Europe, Eastern--History--20th century.
Communist parties--Social aspects--Europe, Eastern.
Communist parties--Social aspects--Soviet Union.
Communist parties--Soviet Union--History.