The manuscripts of His Grace the Duke of Portland, preserved at Welbeck Abbey. - Cartwright, James Joel; Isaacson, R. F.; Nalson, John; Harley, Robert; Portland, William John Arthur Charles James Cavendish-Bentinck; Stratford, William; Ward, Richard. (TannerRitchie Publishing in collaboration with the Library and Information Services of the University of St Andrews, 2013)