Chorn, J. (1978)
Helicoprion (Elasmobranchii, Edestidae) from the Bone Spring Formation (Lower Permian) of West Texas. The University of Kansas Paleontological Contributions, 89, 2–4

Chorn, J. & Reavis, E.A. (1978)
Affinities of the chondrichthyan organ-genera Listracanthus and Petrodus. The University of Kansas Paleontological Contributions, 89, 4–9

Chorn, J. & Reavis, E.A. (1978)
Enterospirae (fossil intestines) from the upper cretaceous Niobrara Formation of Western Kansas. The University of Kansas Paleontological Contributions, 89, 9–16