2010

Neumann, C.; Assahad, G.; Hammerschmidt, K.; Farajallah, D.P.; Engelhardt, A. (2010): Loud calls in male Macaca nigra – a signal of dominance in a tolerant primate species. Animal Behaviour 79: 187-193.

2009

Duboscq, J.; Perwitasari-Farajallah, D.; Engelhardt, A. (2009):  Social Interactions between Females in Wild Crested Macaques, Macaca nigra”, Folia Primatologica, 80, 157.

Engelhardt, A.; Heistermann, M.; Perwitasari-Farajallah, D. (2009): Sex skin colouration in male Sulawesi crested black macaques (Macaca nigra), Primate Eye, 96, 337.

Neumann, C.; Assahad, G.; Hammerschmidt, K.; Perwitasari-Farajallah, D. ; Engelhardt, A. (2009): Male Sexual Signals in Crested Macaques (Macaca nigra)”, Folia Primatologica, 80, 131–2.

2008

Assahad, G.; Neumann, C.; Hammerschmidt, K.; Farajallah, D.P.; Engelhardt, A. (2008): Rank dependant differences in loud call frequency and structure in Sulawesi crested black macaques (Macaca nigra). Folia Primatologica, 79, 311.

Duboscq, J.; Neumann, C.; Perwitasari-Farajallah, D.; Engelhardt, A. (2008): Daytime birth of a baby crested black macaque (Macaca nigra) in the wild. Behavioural Processes 79: 81–84.

Engelhardt, A.; Perwitasari-Farajallah, D. (2008): Reproductive biology of Sulawesi crested black macaques (Macaca nigra). Folia Primatologica, 79, 326.

Neumann, C.; Assahad, G.; Hammerschmidt, K.; Farajallah, D.P.; Engelhardt, A. (2008): Individual and contextual differences in loud calls of male crested black macaques, Macaca nigra. Folia Primatologica, 79, 366.