Authors	Year	Title
Gordon	1965	Carboniferous Cephalopods of Arkansas. Professional Papers, U.S. Geological Survey, 460: 1-322, fig.1-96, pl.1-32; Washington. [imprint 1964].
Moore	1936	The Bowland Shales from Pendle to Dinckley. Journal of the Manchester Geological Association,: 167-192, fig.1-3, pl.1-3; Manchester.
Portlock	1843	Report on the geology of the county of Londonderry, and parts of Tyrone and Fermanagh. I-XXXI, 1-784, fig.1-26, pl.1-38, 1map; Dublin.