Report on the manuscripts of the Earl of Ancaster, preserved at Grimsthorpe
Great Britain. Royal Commission on Historical Manuscripts; Great Britain. Historical Manuscripts Commission. Report on the Pepys manuscripts preserved at Magdalene College, Cambridge, 1911; Ancaster, Gilbert Heathcote-Drummond-Willoughby, 2nd Earl of, 1867-; Bertie family; Willoughby de Eresby, Peregrine Bertie, Baron, 1555-1601