Dormant, Abeyant, Forfeited, and Extinct Peerages @ p. 433, Plantagenet, Barons of Woodstock, Earls of Kent
The cited information was published by Burke's Peerage, Ltd., London, England, 1883, held in
{R500171218} (Ref: p. 433, Plantagenet, Barons of Woodstock, Earls of Kent) The author/originator was Sir Bernard Burke.