1. Observational study of behavior: sampling methods;Altmann;Behaviour,1974
2. Primate longevity: its place in the mammalian scheme;Austad;Am J Primatol,1992
3. Bergeson DJ. 1996. The positional behavior and prehensile-tail use of Alouatta palliata, Ateles geoffroyi, and Cebus capucinus, Ph.D. dissertation, Washington University, St Louis, MO.