Columbia subject headings:
Harvard subject headings:
Communism--Europe, Eastern--History--20th century--Congresses.
Czechoslovakia--History--Intervention, 1968--Congresses.
Czechoslovakia--Politics and government--Congresses.
Europe, Eastern--Politics and government--Congresses.
Princeton subject headings:
Communism--Europe, Eastern--History--20th century--Congresses.
Czechoslovakia--History--Intervention, 1968--Congresses.
Czechoslovakia--Politics and government--Congresses.
Europe, Eastern--Politics and government--Congresses.