Estrada, A.; Belle, S. V.; del Valle, Y. G. A Survey of Black Howler (Alouatta Pigra) and Spider (Ateles Geoffroyi) Monkeys Along the río Lacantún, Chiapas, Mexico. Neotrop. Primates 2004, 12 (2), 70-75. https://doi.org/10.62015/np.2004.v12.574.