The manuscripts of His Grace the Duke of Portland, preserved at Welbeck abbey
Great Britain. Royal Commission on Historical Manuscripts; Portland, William John Arthur Charles James Cavendish-Bentinck, Duke of, 1857-1943; Nalson, John, 1638?-1686; Oxford, Robert Harley, Earl of, 1661-1724; Stratford, William, 1672?-1729; Cartwright, James J. (James Joel), 1842-1903; Ward, Richard