Behringer, V., Deschner, T., Deimel, C., Stevens, J., & Hohmann, G. (2014). Age-related
changes in urinary testosterone levels suggest differences in puberty onset and divergent life history strategies in bonobos
and chimpanzees. Hormones and Behavior, 66(3), 525-533.
doi:10.1016/j.yhbeh.2014.07.011.