	Authors	Year	Title
	Miller & Furnish	1940c	Permian ammonoids of the Guadalupe Mountain Region and adjacent areas. Special Papers of the Geological Society of America, 26: 1-242, fig.1-59, pl.1-44; Baltimore.
	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.