"Cowthick Quarry citation"(PDF). Sites of Special Scientific Interest. Natural England. Archived from the original(PDF) on 3 March 2016. Retrieved 12 February 2017.
web.archive.org
"Cowthick Quarry citation"(PDF). Sites of Special Scientific Interest. Natural England. Archived from the original(PDF) on 3 March 2016. Retrieved 12 February 2017.