Bufalino, Angelo; Scott, Floyd (2008). "Statistical Analyses of Pattern Variation in the Copper-bellied (Nerodia Erythrogaster Neglecta) and Yellow-bellied (N. E. Flavigaster) Watersnake Subspecies". The American Midland Naturalist. 159 (1): 30–41. doi:10.1674/0003-0031(2008)159[30:SAOPVI]2.0.CO;2.
Roe, John H.; Gibson, Joanna; Kingsbury, Bruce A. (1 June 2006). "Beyond the wetland border: Estimating the impact of roads for two species of water snakes". Biological Conservation. 130 (2): 161–168. Bibcode:2006BCons.130..161R. doi:10.1016/j.biocon.2005.12.010.
Roe, John H.; Gibson, Joanna; Kingsbury, Bruce A. (1 June 2006). "Beyond the wetland border: Estimating the impact of roads for two species of water snakes". Biological Conservation. 130 (2): 161–168. Bibcode:2006BCons.130..161R. doi:10.1016/j.biocon.2005.12.010.