Columbia subject headings:
Harvard subject headings:
Germany--History--1990-
Germany--History--Unification, 1990--Anniversaries, etc.
Germany--History--Unification, 1990--Congresses.
Germany--Politics and government--1990---Congresses.
Germany--Social conditions--1990-
Princeton subject headings:
Germany--History--1990-
Germany--History--Unification, 1990--Anniversaries, etc.
Germany--Social conditions--1990-