	Authors	Year	Title
	King, Dunbar & Cloud	1944	Geology and Paleontology of the Permian area northwest of Las Delicias, southwestern Coahuila, Mexico. [King,R.E., Dunbar,C.O., Cloud,P. & Miller,A.K.] Geological Society of America Special Papers, 52: X + 1-172, 29 text-figs., 45 pls.
	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.
	Spinosa, Furnish & Glenister	1975	The Xenodiscidae, Permian ceratitoid ammonoids. Journal of Paleontology, 49 (2): 239-283, fig.1-22, tab.1-5, pl.1-8.