Difley, R. L., and Ekdale, A.A. (2002) Footprints of Utah\\\'s Last Dinosaurs: Track Beds in the Upper Cretaceous (Maastrichtian) North Horn Formation of the Wasatch Plateau, Central Utah. Palaios: Vol. 17, No. 4, pp. 327- 346.
Difley, R., and Ekdale, A. A. (2002) Faunal implications of an environmental change before the Cretaceous-Tertiary (K-T) transition in central Utah: Cretaceous Research, v. 23, p. 315-331.
Difley, R., and Ekdale, A.A. (2006) Trace fossils and paleoenvironments of the Early Jurassic Kayenta Formation, Washington County, Utah; pp. 49-51 in Reynold, R.E. (ed.), Making Tracks Across the Southwest. California State University Desert Studies Consortium and LSA Associates, Inc.
Difley, R. (2007) Biostratigraphy of the North Horn Formation at North Horn Mountain, Emery County, Utah: UGA Publication n. 36, p. 439-454