Krysko, K. L. and Judd, W. S. (2006) “Morphological systematics of kingsnakes, Lampropeltis getula complex (Serpentes: Colubridae), in the eastern United States”, Zootaxa. Auckland, New Zealand, 1193(1), pp. 1–39. doi: 10.11646/zootaxa.1193.1.1.