	Authors	Year	Title
	Furnish & Spinosa	1966	Historic Pennsylvanian Ammonoids from Iowa. Iowa Academy of Science, 73: 253-259, fig.1-2.
	Wiedey	1929	A new species of an exotic group of Carboniferous goniatites. American Journal of Science, 5th Series, Volume 17: 321-325 fig.1-7; New Haven, Conn.