Columbia subject headings:
Harvard subject headings:
Berlin Wall, Berlin, Germany, 1961-1989--Congresses.
Germany--History--Unification, 1990--Congresses.
Germany--Relations--Soviet Union--Congresses.
Soviet Union--Politics and government--1985-1991--Congresses.
Soviet Union--Relations--Germany--Congresses.
Princeton subject headings:
Germany (East)--Politics and government--1989-1990.
Germany--History--Unification, 1990.
Post-communism.
Russia (Federation)--History--1991-
Social change--Germany--History--20th century.
Social change--Soviet Union--History--20th century.
Soviet Union--History--1985-1991.