Columbia subject headings:
German states--History--19th century--Congresses.
German states--History--20th century--Congresses.
Harvard subject headings:
Federal government--Germany--History--Congresses.
German states--History--19th century--Congresses.
German states--History--20th century--Congresses.
Germany--History--1789-1900--Congresses.
Germany--History--20th century--Congresses.
Germany--History--Unification, 1990--Congresses.
Princeton subject headings:
Federal government--Germany--History--Congresses.
Germany--History--19th century--Congresses.
Germany--History--20th century--Congresses.
Germany--History--Unification, 1990--Congresses.