Rattlesnakes are venomous snakes belonging to the family Viperidae, subfamily Crotalinae (pit vipers), and are primarily ...
Klauber, Laurence M. 1930. "Differential characteristics of southwestern rattlesnakes allied to Crotalus atrox." Bulletins of the Zoological Society of San Diego, (6) 1–72, pls. 1-6, map 1-3.