Columbia subject headings:
Harvard subject headings:
Berlin (Germany)--Description and travel
Berlin (Germany)--History--1945-1990
Cold War--Social aspects--Germany (East)
Germans--Germany (East)--Travel--Germany (West)
Germans--Travel--Germany (East)--Germany (West)--Berlin.
Germans--Travel--Germany (East)--Western countries.
Germany (East)--Description and travel.
Germany (East)--History.
Germany (East)--Politics and government.
Travel--History
Travelers--Germany (East)
Travelers--Government policy--Germany (East)
Princeton subject headings:
Berlin (Germany)--Description and travel.
Berlin (Germany)--History--1945-1990.
Germans--Germany (East)--Travel--Germany (West).
Germany (East)--Description and travel.
Germany (East)--History.
Travelers--Germany (East).