Columbia subject headings:
Harvard subject headings:
Communism--Soviet Union
Communist countries--Foreign relations--Soviet Union.
Soviet Union--Foreign relations--Communist countries.
Soviet Union--Politics and government--1917-1936.
Soviet Union--Politics and government.
Princeton subject headings:
Communism--Soviet Union.
Communist countries--Foreign relations--Soviet Union.
Soviet Union--Foreign relations--Communist countries.
Soviet Union--Politics and government.