Columbia subject headings:
Germany--History--1945-1990.
Germany--History--Unification, 1990.
Harvard subject headings:
Berlin Wall, Berlin, Germany, 1961-1989
German reunification question (1949-1990)
Germany (East)--Politics and government.
Germany (West)--Politics and government.
Germany--History--Unification, 1990.
Princeton subject headings:
Berlin Wall, Berlin, Germany, 1961-1989.
Germany--History--1945-1990.
Germany--History--Unification, 1990.