The Cat Ba langur (Trachypithecus poliocephalus), also known as the golden-headed langur, is a critically endangered species of langurendemic to Cát Bà Island, Vietnam. It is among the rarest primates in the world, and possibly the rarest primate in Asia, with population size estimated at less than 70 individuals.[3][4]
^Mittermeier, R. A.; Wallis, J.; Rylands, A. B.; Ganzhorn, J. U.; Oates, J. F.; Williamson, E. A.; Palacios, E.; Heymann, E.W.; Kierulff, M. C. M.; Long Yongcheng; Supriatna, J.; Roos, C.; Walker, S.; Cortés-Ortiz, L.; Schwitzer, C., eds. (November 2009). Primates in Peril: The World's 25 Most Endangered Primates 2008–2010(PDF). Illustrated by S.D. Nash. Arlington, VA.: IUCN/SSC Primate Specialist Group (PSG), International Primatological Society (IPS), and Conservation International (CI). pp. 1–92. ISBN978-1-934151-34-1. Archived from the original(PDF) on 2011-07-23. Retrieved 2010-08-06.
^Stenke, R., Phan Duy Thuc and Nadler, T. 2007. Golden-headed Langur or Cat Ba Langur. In: Primates in Peril: The World's 25 Most Endangered Primates 2006–2008, R. A. Mittermeier et al. (compilers), pp.14-15. Unpublished report, IUCN/SSC Primate Specialist Group (PSG), International Primatological Society (IPS), and Conservation International (CI), Arlington, VA.