Hai, Nguyen Dinh, Nguyen Xuan Nghia, Nguyen Xuan Dang, Dang Huy Phuong, and Nguyen Mau Toan. 2016. “The Status of Indochinese Grey Langur Trachypithcus Crepusculus at Xuan Lien Nature Reserve, Thanh Hoa Province”. Academia Journal of Biology 38 (2):162-70. https://doi.org/10.15625/0866-7160/v38n2.7890.