	Authors	Year	Title
	Bisat	1950	The junction faunas of the Viséan and Namurian. Transactions of the Leeds Geologists Association., 6 (3): 10-26, fig.1, pl.1,2; Kendal.
	Moore	1946	The Carboniferous goniatite genera Girtyoceras and Eumorphoceras. Proceedings of the Yorkshire Geological Society, 25: 387-445, 31 figs., pl.22-27; Wakefield.