Allen, W., Grueter, C. C., Zhu, P., Higham, J. P., Ren, B., & Li, M. (2015). Sexually selected lip colour indicates male group-holding status in the mating season in a multi-level primate society. Royal Society Open Science, 2(12), p. 150490. doi:10.1098/rsos.150490

Allen, William, Cyril C. Grueter, Pingfen Zhu, James P. Higham, Baoping Ren, and Ming Li. "Sexually Selected Lip Colour Indicates Male Group-holding Status in the Mating Season in a Multi-level Primate Society." Royal Society Open Science 2, no. 12 (2015): 150490.

Allen, William, et al. "Sexually Selected Lip Colour Indicates Male Group-holding Status in the Mating Season in a Multi-level Primate Society." Royal Society Open Science 2.12 (2015): 150490.