Columbia subject headings:
Harvard subject headings:
Berlin Wall, Berlin, Germany, 1961-1989
Germany (East)--Politics and government--1989-1990.
Germany--History--Unification, 1990.
Opposition (Political science)--Germany (East)--History.
Socialism--Germany (East)
Socialism--Germany (East)--History
Princeton subject headings:
Berlin Wall, Berlin, Germany, 1961-1989.
Germany (East)--Politics and government--1989-1990.
Germany--History--Unification, 1990.
Oppositon (Political science)--Germany (East)--History.
Socialism--Germany (East)--History.