	Authors	Year	Title
	Bisat & Hudson	1943	The lower Reticuloceras (R1) goniatite succession in the Namurian of the North of England. Proceedings of the Yorkshire Geological Society, 24 (6): 383-440, fig.1, pl.23-30; Wakefield.
	Saunders & Ramsbottom	1993	Re-evaluation of two Early Pennsylvanian (Middle Namurian) ammonoids and their bearing on mid-Carboniferous correlations. Journal of Paleontology, 67: 993-999, 3 figs., Lawrence, KA.