Pereira, Marcia Elisa, et al. “Microscopic Aspects from Howler monkey’s (Alouatta Fusca Clamitans) Lip”. Brazilian Journal of Veterinary Research and Animal Science, vol. 39, no. 1, Jan. 2002, pp. 9-12, https://doi.org/10.1590/S1413-95962002000100001.