See Peter Bartrum, https://cadair.aber.ac.uk/dspace/bitstream/handle/2160/5092/bleddyn... (December 24, 2016; Anne Brannen, curator)

Please see Darrell Wolcott: The "Sons" of Owain ap Cadwgan ap Bleddyn; http://www.ancientwalesstudies.org/id159.html. (Steven Ferry, August 15, 2020.)

Please see Darrell Wolcott: Family of Drymbenog ap Maenyrch of Brycheiniog; http://www.ancientwalesstudies.org/id312.html (Steven Ferry, May 21, 2023.)

Please see Peter Bartrum: Bleddyn ap Cynfyn 55; https://www.geni.com/documents/view?doc_id=6000000173378261966 & Bleddyn ap Cynfyn 2; https://www.geni.com/documents/view?doc_id=6000000173377928114 [Bartrum attempts to provide 2 different lines for this man. Please see the Wolcott works cited above as to how both lines are erroneous] (Steven Ferry, May 15, 2025.)