	Authors	Year	Title
	Bisat	1924	The Carboniferous goniatites of the North of England and their zones. Proceedings of the Yorkshire Geological Society, 20: 40-124, pl.1-10; Leeds.
	Moore	1946	The Carboniferous goniatite genera Girtyoceras and Eumorphoceras. Proceedings of the Yorkshire Geological Society, 25: 387-445, 31 figs., pl.22-27; Wakefield.