Althorp Papers. Vols. dclxi, dclxii. Letters from Thomas Grenville (1755-1845), 1st Lord of the Admiralty (1806-1807) and book-collector; 1793-1834. Two volumes.
Althorp Papers. Vols. dclxiv, dclxv. Letters from Alexander Horne, diplomat; 1794-1819. The letters are written chiefly from Ratisbon and Frankfurt and relate to Horne's role as agent for Spencer's book-collecting. Two volumes.