Yn cynnwys mynegeion = Includes indexes.
Gwaith Siôn ap Hywel ap Llywelyn Fychan by Siôn ap Hywel ap Llywelyn Fychan. ISBN 0947531556. Published by Canolfan Uwchefrydiau Cymreig a Cheltaidd Prifysgol Cymru in 1999. Publication and catalogue information, links to buy online and reader comments.