	Authors	Year	Title
	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.
	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.
	Calver & Ramsbottom	1961	Stratigraphical Palaeontology. In: J.R. Earp et al.: Geology of the Country around Clitheroe an Nelson. Memoir of the Geological Survey of Great Britain, Expl. one-inch Geol. Sheet 68, New Series: 174-207, pl.10,11; London.