Survey of the Black Howler Monkey , Alouatta Pigra , Population at the Mayan Site of Palenque , Chiapas , Mexico

Roo, Q. (1999). Survey of the Black Howler Monkey , Alouatta Pigra , Population at the Mayan Site of Palenque , Chiapas , Mexico, 43(January 2002), 51–58.