Guide to the Dept. of Manuscripts and records, NLW, 1994.The main reference to the parish of Eglwys Newydd is under Abertrinant, with deeds 1716-1807, mainly in the parish of Llanfihangel -y-Creuddyn.
Borron, John R E. The Waddinghams of Hafod (NLW's site) Ceredigion XI
Colyer, Richard. The Hafod Estate under Thomas Johnes and Henry Pelham, fourth Duke of Newcastle (NLW's site) Welsh History Review 8
Cumberland, George. ; Macve, Jennifer. ; Sclater, Andrew. An attempt to describe Hafod Ymddiriedolaeth Yr Hafod, Hafod Trust, Bicentenary ed. 1996 1796. Facsimile of ed. originally published: 1796. - Repr. with new introduction and notes.
Evans, E D. Hafod in the time of the Duke of Newcastle (1785-1851) (NLW's site) Ceredigion XII
Inglis-Jones, Elisabeth. Hafod of Thomas Johnes. Wales, 1946
Kerkham, Caroline and Stephen Briggs. A review of the archaeological potential of the Hafod landscape (NLW's site) Ceredigion XI
Linnard, W. Thomas Johnes of Hafod, Pioneer of Upland Afforrestation in Wales (NLW's site) Ceredigion : Journal of the Cardiganshire Antiquarian Society, Vol VI, No 3, 1970.
Thomas, John. The architectural development of Hafod 1786-1807 & 1807-1882 (2 parts) (NLW's site) Ceredigion Vol VII