Columbia subject headings:
Harvard subject headings:
Berlin Wall, Berlin, Germany, 1961-1989--Congresses.
Cold War--Congresses
Europe, Central--History--1989---Congresses.
Europe, Eastern--History--1989---Congresses.
Germany--History--1945-1990--Congresses.
Germany--History--Unification, 1990--Congresses.
Princeton subject headings:
Berlin Wall, Berlin, Germany, 1961-1989--Congresses.
Cold War--Congresses.
Europe, Central--History--1989---Congresses.
Europe, Central--History--20th century--Congresses.
Europe, Eastern--History--1945-1989--Congresses.
Europe, Eastern--History--1989---Congresses.
Germany--History--1945-1990--Congresses.
Germany--History--Unification, 1990--Congresses.