Columbia subject headings:
Berlin Wall, Berlin, Germany, 1961-1989.
Germany--History--Unification, 1990.
Harvard subject headings:
Berlin Wall, Berlin, Germany, 1961-1989.
Germany--History--Unification, 1990.
Princeton subject headings:
Berlin Wall, Berlin, Germany, 1961-1989.
Germany--History--Unification, 1990.