	Authors	Year	Title
	Girty	1908	The Guadalupian Fauna. Professional Papers, U.S. Geological Survey, 58: 1-651, pl.1-31; Washington.
	Plummer & Scott	1937	Upper Paleozoic ammonites in Texas. The geology of Texas, vol.3 pt.1, Bull. Texas. Univ., 3701: 1-516, fig.1-88, pl.1-41; Austin, Texas.