1. Agassiz, L. 1839. In: Murchison, R. I. The Silurian System. 604–6. London.
2. Deposition of the Catskill Facies, Appalachian Region: with notes on some other Old Red Sandstone basins;Allen;Bull geol Soc Am Spec Paper,1968
3. A Dittonian ostracoderm fauna from the Brownstones of Wilderness Quarry, Mitcheldean, Gloucestershire;Allen;Proc geol Soc Land,1968
4. The Downtonian and Dittonian Facies of the Welsh Borderland;Allen;Geol Mag,1963
5. Armstrong, M. & Paterson, I. B. 1970. The Lower Old Red Sandstone of the Strathmore region. Rep. no. 70/12. Inst. geol. Sci., 1–23.