Zangerl, R. & Winter, H.F. & Hansen, M.C. (1993)
Comparative Microscopic Dental Anatomy in the Petalodontida (Chondrichthyes, Elasmobranchii). Fieldiana Geology, 26, 1–42
Shourd, M.L. & Winter, H.F. (1980)
Paleocene Megafossils from Southeastern Missouri. Journal of Paleontology, 54(4), 832–839