Massey, Adrianne. 1987. “A Population Survey of <i>Alouatta palliata</i>, <i>Cebus capucinus</i> and <i>Ateles geoffroyi</i> At Palo Verde, Costa Rica”. Revista De Biología Tropical 35 (2):345–347. https://revistas.ucr.ac.cr/index.php/rbt/article/view/24116.