Columbia subject headings:
Harvard subject headings:
Germany--History--Unification, 1990.
Germany--Politics and government--1990-
Germany--Relations--Poland.
Poland--Politics and government--1989-
Poland--Relations--Germany
Princeton subject headings:
Germany--History--Unification, 1990.
Germany--Politics and government--1990-
Germany--Relations--Poland.
Poland--Politics and government--1989-
Poland--Relations--Germany.