Columbia subject headings:
Harvard subject headings:
Germany--History--Unification, 1990--Congresses.
Germany--Politics and government--20th century--Congresses.
Kohl, Helmut, 1930-2017--Congresses.
Princeton subject headings:
Germany--Foreign relations--1945-
Germany--Politics and government--1945-1990.
Kohl, Helmut, 1930-2017.