Fröhlich, M., van Noordwijk, M. A., Mitra Setia, T., van Schaik, C. P., & Knief, U. (2024)
Wild and captive immature orangutans differ in their non-vocal communication with others, but not with their mothers
Behavioral Ecology and Sociobiology, 78(1), 12.

Kunz, J. A., Falkner, S. S., Aprilinayati, F., Duvot, G. J., Fröhlich, M., Willems, E. P., ... & van Noordwijk, M. A. (2024).
Play behavior varies with age, sex, and socioecological context in wild, immature orangutans (Pongo spp.).
International Journal of Primatology, 1-35.