Vásquez-Cruz, Víctor, et al. “A Dicephalic Western Dusky Rattlesnake, Crotalus Triseriatus (Squamata: Viperidae)”. Reptiles & Amphibians, vol. 27, no. 3, Nov. 2020, pp. 532-3, https://doi.org/10.17161/randa.v27i3.14913.