Traddodywd y ddarlith = Lecture delivered: 8/10/92, Ysgol Bro Lleu.
Hafan, bwlch a dyffryn by Elfed Roberts. ISBN 0901337552. Published by Cyngor Sir Gwynedd, Adran Diwylliant a Hamdden in 1993. Publication and catalogue information, links to buy online and reader comments.