Columbia subject headings:
Communist countries--Relations--Soviet Union.
Europe, Eastern--Relations--Soviet Union.
Soviet Union--Relations--Communist countries.
Soviet Union--Relations--Europe, Eastern.
Harvard subject headings:
Communist countries--Relations--Soviet Union.
Europe, Eastern--Relations--Soviet Union.
Soviet Union--Relations--Communist countries.
Soviet Union--Relations--Europe, Eastern.
Princeton subject headings:
Communist countries--Relations--Soviet Union.
Europe, Eastern--Relations--Soviet Union.
Soviet Union--Relations--Communist countries.
Soviet Union--Relations--Europe, Eastern.