Columbia subject headings:
Harvard subject headings:
Prussia (Germany)--History--1815-1870.
Schleswig-Holstein (Germany)--History--19th century.
Schleswig-Holstein (Germany)--Kings and rulers.
Princeton subject headings:
Prussia (Germany)--History--1815-1870.
Schleswig-Holstein (Germany)--History--19th century.
Schleswig-Holstein (Germany)--Kings and rulers.