	Authors	Year	Title
	Wardlaw, Rudine & Nestell	2000	Conodont Biostratigraphy of the Permian Beds at Las Delicias, Coahuila, Mexico. In: Wardlaw,B.R., Grant,R.E. & Rohr,D.M.: The Guadalupian Symposium, Smithsonian Contributions to the Earth Sciences, 32, 381-392, 10 fig., 1 pl., Washington.