	Authors	Year	Title
	Manger & Saunders	1980	Lower Pennsylvanian (Morrowan) ammonoids from the North American midcontinent. Journal of Paleontology, 54, Suppl.(3): 1-56, fig.1-21, pl.1-6, tab.1-10; Tulsa, Okla.
	Smith	1903	The Carboniferous Ammonoids of America. Monography, U.S. geological Survey, 42: 1-211, pl.1-29; Washington.