Columbia subject headings:
Harvard subject headings:
Germany--Economic conditions--1990---Congresses.
Germany--History--Unification, 1990--Congresses.
Germany--Social conditions--1990---Congresses.
Princeton subject headings:
Germany--Economic conditions--1990---Congresses.
Germany--History--Unification, 1990--Congresses.
Germany--Social conditions--1990---Congresses.