Columbia subject headings:
Censorship--Soviet Union--Congresses.
Freedom of information--Soviet Union--Congresses.
Government information--Soviet Union--Congresses.
Official secrets--Soviet Union--Congresses.
Harvard subject headings:
Censorship--Russia--History--Congresses.
Censorship--Soviet Union--Congresses.
Freedom of information--Soviet Union--Congresses.
Government information--Soviet Union--Congresses.
Official secrets--Soviet Union--Congresses.
Princeton subject headings: