Columbia subject headings:
Europe, Eastern--Foreign relations--Soviet Union--Congresses.
Soviet Union--Foreign relations--Europe, Eastern--Congresses.
Harvard subject headings:
Europe, Eastern--Foreign relations--Soviet Union--Congresses.
Soviet Union--Foreign relations--Europe, Eastern--Congresses.
Princeton subject headings:
Europe, Eastern--Foreign relations--Soviet Union--Congresses.
Russia--Foreign relations--Europe, Eastern--Congresses.