Columbia subject headings:
Hardenberg, Karl August, Fürst von, 1750-1822.
Prussia (Germany)--Foreign relations--1786-1806.
Harvard subject headings:
Hardenberg, Karl August, Fürst von, 1750-1822.
Prussia (Germany)--Foreign relations--1786-1806.
Princeton subject headings:
Hardenberg, Karl August, Fürst von, 1750-1822.
Prussia (Germany)--Foreign relations--1786-1806.