Correspondence of Edmund Burke. I. P. 231–233; Prologue. P. 130–131; The American Correspondence of a Bristol Merchant, 1766–1776: Letters of Richard Champion. Berkeley and London, 1934. P. 9–12; Sutherland L. S. Edmund Burke and the First Rockingham Ministry // Essays in Eighteenth-Century History from the English Historical Review. London, 1966. P. 45–71.