Columbia subject headings:
Communism--China--Congresses.
Communism--Europe, Eastern--Congresses.
Communism--Europe--Congresses.
Communist state--Congresses.
Harvard subject headings:
Communism--China--Congresses
Communism--Europe, Eastern--Congresses.
Communism--Europe--Congresses
Communist state--Congresses.
Princeton subject headings:
Communism--China--Congresses.
Communism--Europe, Eastern--Congresses.
Communism--Europe--Congresses.
Communist state--Congresses.