Authors	Year	Title
Figge	1968	A Goniatite fauna from the Visean/Namurian boundary. Palaeontology, 11: 264-274, fig.1-2, pl.46,47; London.
Korn & Tilsley	2002	A well preserved early Namurian ammonoid fauna with Cravenoceras leion Bisat 1930 from Backdale Mine, Hassop, Derbyshire, England. Proceedings of the Yorkshire Geological Society, 54 (2): 111-119.
Yates	1961	New Namurian goniatites of the genus Eumorphoceras. Palaeontology, 4: 54-58, pl.6; London.