Geological notes and local details for 1:10000 sheet SO20SE (Abersychan - Pontypool) : part of 1:50000 sheets 232 (Abergavenny) and 249 (Newport): Institute of Geological Sciences, Geological notes and local details for 1:10000 sheets, 1984 - 13p / W.J.Barclay, D.I.Jackson and H.C.SquirrellBooks/Monographs
