Columbia subject headings:
Nobility--Germany--History--Congresses.
Harvard subject headings:
Aristocracy (Social class)--Germany--History--Congresses.
Germany--History--Congresses.
Nobility--Germany--History--Congresses.
Princeton subject headings:
Aristocracy (Social class)--Germany--History--Congresses.
Germany--History--Congresses.
Nobility--Germany--History--Congresses.