Phillimore 1887:87, Pedigrees from Jesus College MS. 20 – The genealogical line for Merfyn's son
Rhodri Mawr traces all the way back to Coel Hen through Llywarch Hen: "Rodri ma6r. M. Meruyn vrych. M. G6rhyat. M. Elidyr. M. sandef. M. Alcun. M. tegyth. M. Ceit. M. douc. M. Llewarch hen. M. Elidyr lydanwyn. M. Meircha6n. M. G6rgust. M. Keneu. M. Coil hen. mal y mae vchot." A subsequent pedigree traces Rhodri's ancestry back to Maxen wledig through Gwriad's paternal grandmother. Phillimore, Egerton, ed. (1887), "Pedigrees from Jesus College MS. 20", Y Cymmrodor, vol. VIII, Honourable Society of Cymmrodorion, pp. 83–92
Parry 1829:63, Brut y Saeson. Parry, Henry, ed. (1829), "Brut y Saeson", Archaeologia Cambrensis, Third, vol. IX, London: J. Russell Smith (published 1863), p. 63
Skene 1868b:368, Red Book of Hergest, Three kings, who were of the sons of strangers: Gwryat, son of Gwryan yn y Gogled; and Cadafel, son of Cynfedw in Gwynedd; and Hyreidd Hir, son of Bleidic in Deheubarth. Skene, William Forbes (1868b), The Four Ancient Books of Wales, vol. II, Edinburgh: Edmonston and Douglas (published 1868)