Elen verch Owain

See Peter Bartrum, https://cadair.aber.ac.uk/dspace/bitstream/handle/2160/5183/Bleddyn... (May 30, 2017; Anne Brannen, curator)

See Darrell Wolcott, http://www.ancientwalesstudies.org/id140.html -- for a discussion of three different Iorwerths Goch, often conflated in the medieval manuscripts, and a method for untangling them. (May 27, 2017; Anne Brannen, curator)

See Peter Bartrum, https://www.geni.com/documents/view?doc_id=6000000173392791978 (November 8, 2022; Anne Brannen, curator)

Please see Darrell Wolcott: Three Men Called Iorwerth Goch "ap Maredudd"; http://www.ancientwalesstudies.org/id140.html. (Steven Ferry, September 6, 2020.)

Bartrum calls her Elen, Wolcott calls her Efa:
Please see Peter Bartrum: Tudur Trevor 10; https://www.geni.com/documents/view?doc_id=6000000173392791978 & Bleddyn ap Cynfyn 41; https://www.geni.com/documents/view?doc_id=6000000173378013031 (Steven Ferry, April 25, 2023.)