Hartstein, E.F. & Decina, L.E. (1986)
A new Severn Formation (Early Middle Maastrichtian, Late Cretaceous) locality in Prince Georges County, Maryland. The Mosasaur, 3, 87–96
Lauginiger, E.M. & Hartstein, E.F. (1983)
A guide to fossil sharks, skates, and rays from the Chesapeake and Delaware Canal area, Delaware. Open File Report, 21, 6–95