Columbia subject headings:
Harvard subject headings:
Czechoslovakia--History--Intervention, 1968.
Czechoslovakia--Politics and government--1968-1989.
Europe, Eastern--Politics and government--1945-1989.
Princeton subject headings:
Czechoslovakia--History--Intervention, 1968.
Czechoslovakia--Politics and government--1968-1989.
Europe, Eastern--Politics and government--1945-1989.