1. Studies in fluviatile sedimentation: six cyclothems from the Lower Old Red Sandstone, Anglo-Welsh Basin;Allen;Sedimentology,1964
2. The succession of the Lower Old Red Sandstone (Siluro-Devonian) along the Ross-Tewkesbury Spur Motorway (M.50), Hereford and Worcester;Allen;Geol. J.,1976
3. The Old Red Sandstone of Brown Clee Hill and the adjacent area. I. Stratigraphy;Ball;Bull. Br. Mus. Nat. Hist. Geol.,1961
4. The early history of land plants;Banks,1968
5. Barclay, W.J., Wilby, P.R., 2003. Geology of the Talgarth district. Sheet Explanation of the British Geological Survey. 1:50,000 Sheet 214 Talgarth (England and Wales).