Smith, G. ., Unguez, G. ., & RM, R. . , Jr. NADPH-diaphorase activity and nitric oxide synthase-like immunoreactivity colocalize in the electromotor system of four species of gymnotiform fish. Brain, Behavior and Evolution, 58(3), 122-36. https://doi.org/10.1159/000047267 (Original work published 2001)