Manuscripts
Manuscript:
Aberystwyth, National Library of Wales, Peniarth MS 15
  • s. xiv / s. xv
Conley, Kassandra, “Various things of great worth: the wonders of India and Wales in Peniarth 15”, Proceedings of the Harvard Celtic Colloquium 30 (2010): 61–81.
Thomas, Peter Wynn [ed.], D. Mark Smith, and Diana Luft [transcribers and encoders], Welsh prose (Rhyddiaith Gymraeg) 1300–1425, Online: Cardiff University, 2007–present. URL: <http://www.rhyddiaithganoloesol.caerdydd.ac.uk>.
“NLW MS. Peniarth 15”
Mittendorf, Ingo, “Y Groglith dyw Sul y Blodeu: die mittelkyrnrische Passion nach Matthäus in Peniarth 14 und Havod 23”, in: Erich Poppe, and Hildegard L. C. Tristram (eds), Übersetzung, Adaptation und Akkulturation im insularen Mittelalter, 4, Münster: Nodus Publikationen, 1999. 259–288.
Edwards, Gwilym Lloyd, Ystorya gwlat Ieuan Vendigeit (llythyr y Preutur Siôn): cyfieithiadau Cymraeg Canol o ‘Epistola Presbyteri Johannis’, Cardiff: University of Wales Press, 1999.  
abstract:

A critical study of a Welsh translation of Ystorya Gwlat Ieuan Vendigeit, a letter supposedly sent by Prester John to Manuel, emperor of Constantinople about 1165, comprising presentations of two translations of the document, taken from manuscripts Jesus College 119, Peniarth 15, 47 and 267, an appreciation of the text and its significance in Welsh literature, and detailed notes.

Huws, Daniel, “Y llawysgrifau”, in: Thomas Jones, Ystoryaeu Seint Greal, ed. J. E. Caerwyn Williams, vol. 1: Y keis, Cardiff: University of Wales Press, on behalf of the Board of Celtic Studies, 1992. xii–xx.
Lloyd-Morgan, Ceridwen, “The Peniarth 15 fragment of Y Seint Greal: Arthurian tradition in the late fifteenth century”, Bulletin of the Board of Celtic Studies 28 (1978): 73–82.
Richard, Melville, “Buchedd Fargred [part 1]”, Bulletin of the Board of Celtic Studies 9:4 (1939, 1937–1939): 324–334.
Evans, J. Gwenogvryn, Report on manuscripts in the Welsh language, vol. 1: Peniarth, Historical Manuscripts Commission, London, 1899.
Internet Archive: <link>
334   “MS 15”
Hen. 57