Columbia subject headings:
Europe--Politics and government--1848-1871.
Prussia (Germany)--Foreign relations--1815-1870.
Harvard subject headings:
Europe--Politics and government--1848-1871.
Prussia (Germany)--Foreign relations--1815-1870.
Princeton subject headings:
Europe--Politics and government--1848-1871.
Prussia (Germany)--Foreign relations--1815-1870.