	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.
	Bisat	1928	The Carboniferous goniatite zones of England and their continental equivalents. Congrès de Stratigraphie Carbonifère, Heerlen 1927, C.R.B.: 117-133, pl.6, 6a; Liège.