1 2 Conant, R. 1975. A Field Guide to Reptiles and Amphibians of Eastern and Central North America, Second Edition. Houghton Mifflin. Boston. 429 pp. (Genus Heterodon and species Heterodon platyrhinos, pp. 168-170 + Plate 25 + Map 130.)
↑ Klemens, MW (1993). “Amphibians and Reptiles of Connecticut and Adjacent Regions”. State Geological and Natural History Survey of Connecticut.
↑ Therres, GD (1999). “Wildlife species of regional conservation concern in the northeastern United States”. Northeast Wildlife.
↑ Seburn, D (2009). “Recovery strategy for the eastern hognose snake (Heterodon platirhinos) in Canada.”. Species at risk act recovery series.
↑ NEPARC. 2010. Northeast amphibian and reptile species of regional responsibility and conservation concern. Northeast Partners in Amphibian and Reptile Conservation (NEPARC) Publication 2010-1.
↑ Ernst, CH and EM (2003). Snakes of the United States and Canada. Smithsonian Books.
↑ Gibbons, J.W., Scott, D.E., Ryan, T.J., Buhlmann, K.A., Tuberville, T.D., Metts, B.S., Greene, J.L., Mills, T.,Leiden, Y., Poppy, S., and C.T. Winne. 2000. The global decline of reptiles, déjà vu amphibians. BioScience 50: 653-666.
1 2 Goin, C.J.; O.B. Goin; G.R. Zug. 1978. Introduction to Herpetology, Third Edition. W.H. Freeman. San Francisco. xi + 378 pp. ISBN 0-7167-0020-4. (Heterodon, pp. 167, 328-329.)
↑ Schmidt, K.P., and D.D. Davis. 1941. Field Book of Snakes of the United States and Canada. G.P. Putnam's Sons. New York. 365 pp. (Heterodon contortrix, pp. 115-118, Figures 25-26 + Plate 11.)
↑ Smith, H.M., and E.D. Brodie, Jr. 1982. Reptiles of North America: A Guide to Field Identification. Golden Press. New York. 240 pp. ISBN 0-307-13666-3. (Genus Heterodon and species Heterodon platyrhinos, pp. 164-167.)
↑ Boulenger, G.A. 1894. Catalogue of the Snakes in the British Museum (Natural History). Volume II., Containing the Conclusion of the Colubridæ Aglyphæ. Trustees of the British Museum (Natural History). Luân Đôn. xi + 382 pp. + Plates I.- XX. (Heterodon platyrhinus, pp. 154-156.)
