Columbia subject headings:
Harvard subject headings:
Germany (East)--History--Congresses.
Germany--History--1990---Congresses.
Princeton subject headings:
German reunification question (1949-1990)--History--Congresses.
Germany (East)--Relations--Germany (West)--Congresses.
Germany (West)--Relations--Germany (East)--Congresses.
Germany--History--1990---Congresses.