Columbia subject headings:
Harvard subject headings:
Frederick II, King of Prussia, 1712-1786.
Prussia (Germany)--History--1640-1740.
Prussia (Germany)--History--Frederick II, 1740-1786.
Prussia (Germany)--Kings and rulers--Correspondence.
Princeton subject headings:
Frederick II, King of Prussia, 1712-1786--Correspondence.
Prussia (Germany)--History--Frederick II, 1740-1786--Sources.