Columbia subject headings:
Harvard subject headings:
Anti-communist movements--Germany (East)--Congresses.
Berlin Wall, Berlin, Germany, 1961-1989--Congresses.
Germany (East)--Politics and government--1989-1990--Congresses.
Germany--History--Unification, 1990--Congresses.
Princeton subject headings:
Germany--History--1990---Congresses.
Germany--History--Unification, 1990--Congresses.
Germany--Social conditions--1990---Congresses.