See Peter Bartrum, https://www.geni.com/documents/view?doc_id=6000000173392955978 Sandde Hardd 4 (April 4, 2025; Anne Brannen, curator)

See Peter Bartrum, https://www.geni.com/documents/view?doc_id=6000000173392989892 Sandde Hardd 3 (April 2, 2025; Anne Brannen, curator)

See Peter Bartrum, https://www.geni.com/documents/view?doc_id=6000000173392255922 (February 25, 2023; Anne Brannen, curator)

See Darrell Wolcott, "The Pedigree of Cynddelw Gam," http://www.ancientwalesstudies.org/id94.html for untangling and clarification of these lines. (February 25, 2016, Anne Brannen, curator)

Please see Darrell Wolcott: Pedigree of Cynddelw Gam of Ystrad Alun; http://www.ancientwalesstudies.org/id94.html; [#156] [#199] (Steven Ferry, November 28, 2017.)

Please see Darrell Wolcott: The Unknown Cadwgan; http://www.ancientwalesstudies.org/id246.html. (Steven Ferry, November 21, 2020.)