Rushton, A.W.A., Owen, A.W., Owens, R.M. & Prigmore, J.K. 2000. British Cambrian to Ordovician Stratigraphy. Geological Conservation Review Series No. 18, JNCC, Peterborough, ISBN 1 86107 4727.
The original source material for these web pages has been made available by the JNCC under the Open Government Licence 3.0. Full details in the JNCC Open Data Policy