Columbia subject headings:
Harvard subject headings:
Frederick II, King of Prussia, 1712-1786.
Germany--History--Revolution, 1848-1849--Sources.
Historiography.
Intellectuals--Germany--Berlin--Biography.
Köppen, K. F. (Karl Friedrich), 1808-1863.
Princeton subject headings:
Hegel, Georg Wilhelm Friedrich, 1770-1831--Criticism and interpretation.
Köppen, K. F. (Karl Friedrich), 1808-1863.