Columbia subject headings:
Harvard subject headings:
Hardenberg, Karl August, Fürst von, 1750-1822.
Prussia (Germany)--History--1740-1815.
Statesmen--Germany--Prussia--Biography.
Princeton subject headings:
Hardenberg, Karl August, Fürst von, 1750-1822.
Prussia (Germany)--History--Frederick William III, 1797-1840.
Prussia (Germany)--Politics and government--1806-1848.