| Ref ID | Type | Author | Date | Title |
|
17867
| Journal Article | Balfour, P.S., D. Brown, E.W. Stitt, K. Grinsell, and A.K. Buchanan | 2007 | Geographic Distribution: Nerodia sipedon (Northern Watersnake). USA: California: Placer Co. |
|
20979
| Other | DeLorme. | 2001 | South Dakota Atlas and Gazetteer. |
|
26212
| Database | GBIF | 2013 | Global Biodiversity Information Facility (GBIF) Database. |
|
25971
| Database | Natural History Museum of Los Angeles County | 2013 | Natural History Museum of Los Angeles County vertebrate collection. Accessed through GBIF data portal, http://data.gbif.org/datasets/resource/14305 |
|
26614
| Journal Article | Rose, J.P., O.J. Miano, and B.D. Todd | 2013 | Trapping efficiency, demography, and density of an introduced population of northern watersnakes, Nerodia sipedon, in California. |
