Columbia subject headings:
Labor unions--Soviet Union.
Soviet Union--Description and travel.
Soviet Union--Economic conditions--1917-1945.
Soviet Union--Social conditions.
Working class--Soviet Union.
Harvard subject headings:
Labor unions--Soviet Union
Labor--Soviet Union
Soviet Union--Description and travel.
Soviet Union--Economic conditions--1917-1945.
Soviet Union--Social conditions.
Working class--Soviet Union
Princeton subject headings: