Wallace, R. B.; Painter, R. L. E.; Taber, A. B.; Ayres, J. M. Notes on a Distributional River Boundary and Southern Range Extension for Two Species of Amazonian Primates. Neotrop. Primates 1996, 4 (4), 149-151. https://doi.org/10.62015/np.1996.v4.353.