Columbia subject headings:
Communism--Europe, Central--Congresses.
Communism--Europe, Eastern--Congresses.
State, The--Congresses.
Harvard subject headings:
Communism--Europe, Central--Congresses.
Communism--Europe, Eastern--Congresses.
State, The--Congresses
Princeton subject headings:
Communism--Europe, Central--Congresses.
Communism--Europe, Eastern--Congresses.
State, The--Congresses.