Columbia subject headings:
Soviet Union--History--Revolution, 1917-1921.
Harvard subject headings:
Communism--Congresses
Communist countries--Foreign relations--Congresses.
Communist countries--Politics and government--Congresses.
Communist parties--Congresses.
Kommunisticheskai͡a partii͡a Sovetskogo Soi͡uza--Congresses.
Soviet Union--History--Revolution, 1917-1921--Influence--Congresses.
Princeton subject headings: