Columbia subject headings:
Labor unions--Soviet Union--History.
Soviet Union--History--1917-1936.
Soviet Union--History--Revolution, 1917-1921.
Harvard subject headings:
Labor unions--Soviet Union--History
Soviet Union--Politics and government--1917-1936.
Princeton subject headings:
Labor unions and communism--Soviet Union--History.
Soviet Union--Politics and government--1917-1936.