	Authors	Year	Title
	Gordon	1965	Carboniferous Cephalopods of Arkansas. Professional Papers, U.S. Geological Survey, 460: 1-322, fig.1-96, pl.1-32; Washington. [imprint 1964].
	Zakharov	1969	Novye dannye k stratigrafii Namiura po ammonoideiam khr. Karachatyr. Doklady Akademii Nauk SSSR 1969, 185 (1): 149-151, 1 text-fig., Moskva.