Coudrat, C.N.Z., Quyet, L.K., Duc, H., Phiaphalath, P., Rawson, B.M., Nadler, T., Ulibarri, L. & Duckworth, J.W.: Pygathrix nemaeusIUCN Red List of Threatened Species. Version 2020-2. 2020. International Union for Conservation of Nature, IUCN, Iucnredlist.org. Viitattu 9.7.2020. (englanniksi)