	Authors	Year	Title
	Bisat	1930	On the goniatite and nautiloid fauna of the middle coal measures of England and Wales. Summary of Progress of the Geological Survey of Great Britain for 1929: 75-89, pl.7-8.
	Librovitch	1939	Klass Golovonogie - Cephalopoda. Otriad Ammonoidea. In: Atlas rukovodiashchikh form iskopaemykh faun SSSR, tom 5. Srednii i verkhnii otdely kamennougol'noi sistemy. Tsentralnii Nauchno-issledovatel'skii Geologo-razvedochnii Institut (TsNIGRI), p.134-141, fig.25-37, tabl.34, Leningrad.