PORTLAND PAPERS. Vol. CCCCXCVII (29/116{1}). Correspondence with Martha, his wife; 1726-1749. Edward Harley, 3rd Earl of Oxford: Martha Harley, née Morgan; wife of Edward, 3rd Earl of Oxford: Correspondence between 3rd Lord and Lady Oxford: 1726-1749.
PORTLAND PAPERS. Vol. CCCCXCVIII (29/116{2}). General correspondence, arranged alphabetically. Edward Harley, 3rd Earl of Oxford: General correspondence: bef. 1755.
PORTLAND PAPERS. Vol. DIII (29/363{1}, 364{1}). Papers of the Cavendish Family of Welbeck, Dukes of Newcastle; 1613-1692, n.d. See also Add. Ch. 76765. Cavendish family; of Welbeck: Papers: 1604-1716, n.d.
PORTLAND PAPERS. Vol. DIV (29/363{2}, 364{2}). 1. Papers of John Holles, Baron Houghton, 4th Earl of Clare, Duke of Newcastle; 1686-1710, n.d. 2. Papers of Margaret (née Cavendish), wife of John Holles, Duke of Newcastle; after 1710-1716. 3. Portland Papers; 1762-after 1782. 4. Letter of...