↑ Poucher, W.A. (1946). "The Backbone of England. A photographic and descriptive guide to the Pennine range from Derbyshire to Durham". Guildford and Esher: Billing and Sons Limited. Cite journal requires |journal= (help)CS1 maint: ref=harv (link)
↑ Edwards, W.; Trotter, F.M. (1975). The Pennines and Adjacent Areas. Handbooks on the Geology of Great Britain (Third ed.). London: HMSO (published 1954). p. 1. ISBN0-11-880720-X.CS1 maint: ref=harv (link)
