van Roosmalen, M. G. M., van Roosmalen, T., & Mittermeier, R. A. (2002). A taxonomic review of the titi monkeys, genus Callicebus Thomas, 1903, with the description of two new species, Callicebus bernhardi and Callicebus stephennashi, from Brazilian Amazonia. Neotropical Primates, 10(Supplement), 1-52. https://doi.org/10.62015/np.2002.v10.503