Hafan, bwlch a dyffryn /
Roberts, Elfed.
Gwynedd (Wales).Adran Diwylliant a Hamdden.
Caernarfon : Cyngor Sir Gwynedd, Adran Diwylliant a Hamdden,
1993.
Traddodywd y ddarlith = Lecture delivered: 8/10/92, Ysgol Bro Lleu.