Columbia subject headings:
Harvard subject headings:
North Rhine-Westphalia (Germany)--History--Exhibitions.
Prussia (Germany)--History--Exhibitions.
Prussians--Germany--North Rhine-Westphalia--Exhibitions.
Princeton subject headings:
North Rhine-Westphalia (Germany)--History--Exhibitions.
Prussia (Germany)--History--Exhibitions.
Prussians--Germany--North Rhine-Westphalia--Exhibitions.