Clinical effects and plasma concentrations of fentanyl after transmucosal administration in three species of great ape.
Hunter, Robert P, Ramiro Isaza, James W Carpenter, and David E Koch. 2004. “Clinical Effects and Plasma Concentrations of Fentanyl After Transmucosal Administration in Three Species of Great Ape”. Journal of Zoo and Wildlife Medicine : Official Publication of the American Association of Zoo Veterinarians 35 (2): 162-6.