"The treaty part you must chiefly acquire by reading the treaties themselves, and the histories and memoirs relative to them; not but that inquiries and conversations upon those treaties will help you greatly, and imprint them better in your mind."
— Stanhope, Philip Dormer, fourth earl of Chesterfield (1694-1773)
(I.cxi, p. 224, BATH, March 1, O. S. 1748.)
Reading David Roberts' edition of Lord Chesterfield's Letters (Oxford: OUP, 1998); and searching text from Project Gutenberg <Link>
Consulting and citing, where possible, Letters Written by the late Right Honourable Philip Dormer Stanhope, Earl of Chesterfield, to his son, Philip Stanhope, Esq. (London: Printed for J. Dodsley, 1774). <Link to ECCO>
See also Miscellaneous Works of the late Philip Dormer Stanhope, Earl of Chesterfield: Consisting of letters to his Friends, never before printed, and Various Other Articles. 2 vols. (London: Printed for Edward and Charles Dilly, 1777). <Link to ECCO>