Columbia subject headings:
Berg (Germany : Duchy)--History--Exhibitions.
Jülich (Germany : Duchy)--History--Exhibitions.
Kleve (Germany : Duchy)--History--Exhibitions.
Harvard subject headings:
Princeton subject headings:
Art, German--Germany--North-Rhine-Westphalia--Exhibitions.
Nobility--Germany--Exhibitions.
North Rhine-Westphalia (Germany)--History--Exhibitions.