Columbia subject headings:
Harvard subject headings:
Frederick II, King of Prussia, 1712-1786--Friends and associates.
Frederick II, King of Prussia, 1712-1786.
Philosophy--Political aspects.
Voltaire, 1694-1778
Wolff, Christian, Freiherr von, 1679-1754.
Princeton subject headings:
Frederick II, King of Prussia, 1712-1786--Friends and associates.
Frederick II, King of Prussia, 1712-1786.
Philosophy--Political aspects.
Voltaire, 1694-1778.
Wolff, Christian, Freiherr von, 1679-1754.