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Nickerson, Max A., Kenneth L. Krysko, and Richard D. Owen. "Ecological Status of the Hellbender (Cryptobranchus alleganiensis) and the Mudpuppy (Necturus maculosus) Salamanders in the Great Smoky Mountains National Park." Journal of the North Carolina Acadmey of Science  118, no. 1 (2002): 27-34.