| Author |
Title  |
Year |
Publication |
Serial |
Volume |
Pages |
| Suda, C.; Call, J. |
Piagetian conservation of discrete quantities in bonobos (Pan paniscus), chimpanzees (Pan troglodytes), and orangutans (Pongo pygmaeus) |
2005 |
Animal Cognition |
2494 |
8 |
220-235 |
| Morton, D.B. |
Self-consciousness and animal suffering |
2000 |
Biologist (London, England) |
618 |
47 |
77-80 |
| Stoinski, T.S.; Whiten, A. |
Social learning by orangutans (Pongo abelii and Pongo pygmaeus) in a simulated food-processing task |
2003 |
Journal of comparative psychology (Washington, D.C. : 1983) |
737 |
117 |
272-282 |
| Van Schaik, C. |
Why are some animals so smart? |
2006 |
Scientific American |
2830 |
294 |
64-71 |
