There are student editions of the poems of Dafyd ap Gwilym, and of Y Gododdin, the strange, and rather difficult medieval Welsh epic poem about the battle of the men of the north at Catraeth, part of the Welsh contribution to Celtic Arthurian literature.

the Pedeir Keinc y Mabinogi edited by Ifor Williams from the White Book manuscript is still the standard edition of the four branches; it includes lengthy notes as well as the edited text, all in Welsh.

Checklist of Middle Welsh Particles by Professor David Klausner at the University of Toronto.

Mediaeval and Modern Welsh Series