	Authors	Year	Title
	Böse	1919	The Permo-Carboniferous ammonoids of the Glass Mountains, west Texas, and their stratigraphical significance. [1919, inscribed 1917]. University of Texas Bulletin, 1762: 1-241, 11 pl., Austin,Texas.
	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.