About Iorwerth ap Cynan, "Drwyndwn"
Please see Darrell Wolcott; "Bartrum's Pedigrees of the Welsh Tribal Patriarchs" - #11 - Llywarch Howlbwrch, http://www.ancientwalesstudies.org/id179.html. (Steven Ferry, March 12, 2017.)
Please see Darrell Wolcott: The Muddled Pedigrees of Sir John Wynn of Gwydir; http://www.ancientwalesstudies.org/id115.html. (Steven Ferry, May 1, 2017.)