1. Agassiz, L. 1871. On the method of copulation among selachians. Proc. Boston Soc. Nat. Hist. 14: 339–341.
2. Bigelow, H.B. and W.C. Schroeder. 1953. Fishes of the Gulf of Maine. U.S. Fish Wild]. Serv. Fish. Bull. 53: 351–357.
3. Bolau, H. 1881. Über die Paarung and Fortpflanzung der Scyllium-Arten. Z. wiss. Zool. 35: 321–325.
4. Bres, M. 1993. The behaviour of sharks. Rev. Fish Biol. Fisheries. 3: 133–159.
5. Brockmann, F.W. 1975. An observation of mating behavior of the southern stingray, Dasyatis americana. Copeia 1975: 784–785.