- [S29] #798 The Wallop Family and Their Ancestry, Watney, Vernon James, (4 volumes. Oxford: John Johnson, 1928), FHL book Q 929.242 W159w; FHL microfilm 1696491 items 6-9., vol. 2 p. 241.
- [S81] #242 [1831 edition] A General and Heraldic Dictionary of the Peerages of England, Ireland, and Scotland, Extinct, Dormant, and in Abeyance (1831), Burke, John, (London: Henry Colburn and Richard Bentley, 1831), FHL book 942 D22bg 1831; FHL microfilm 845,453 item 2., p. 149.
"Ralph de Cromwell, paying a fine of sixty marks and a palfrey to make his peace for participating in the rebellion of the barons; and upon delivering up his eldest daughter in hostage, obtaining restitution of his lands. After which, in 1218-9, he was constituted justice itinerant in the counties of Lincoln, Nottingham, and Derby."