7Karpinsky A.Ueber die Reste von Edestiden und die neue Gattung Helicoprion.Russ K K min.Gesell Verh,Ser 2,1899,36:361-476.
8Wheeler H E.Helicoprion in the Anthracolithic (late Paleozoic) of Nevada and California,and its stratigraphic significance.J Paleontol,1939,13(1):103-114.
9Bendix-Almgreen S E.New investigations on Helicoprion from the Phosphoria Formation of South-east Idaho,USA.Dan Vidensk Selsk.Biol Skr,1966,14(5):1-54.
10Kelly M A,Zangerl R.Helicoprion (Edestidae) in the Permian of West Texas.J Paleontol,1976,50:992-994.
