	Authors	Year	Title
	Manger & Pareyn	1979	New Carboniferous dimorphoceratid ammonoids from Algeria and Arkansas. Journal of Paleontology, 53 (3): 657-665, fig.1-3, pl.1.
	Ruan & Zhou	1987	Carboniferous cephalopods in Ningxia Hui Autonomous Region. [In Chinese, with Engl. summary]. Namurian Strata and Fossils of Ningxia, China: 55-177, 78 text-figs., 15 pls., Nanjing.