Meshaka, Walter E., Jr., and Pablo R. Delis. “Clutch Sizes in Two Populations of the Eastern Garter Snake (Thamnophis Sirtalis) in Pennsylvania”. Reptiles & Amphibians, vol. 17, no. 4, Dec. 2010, pp. 206-20, https://doi.org/10.17161/randa.v17i4.16125.