Nan และ Chen. (1995) Ecology of the black-crested gibbon (Hylobates concolor) in the Ailao Mt. Reserve, Yunnan, China. Mahidol University,:ม.ป.ท.Nan และ Chen. 1995. Ecology of the black-crested gibbon (Hylobates concolor) in the Ailao Mt. Reserve, Yunnan, China. ม.ป.ท.:Mahidol University,;Nan และ Chen. Ecology of the black-crested gibbon (Hylobates concolor) in the Ailao Mt. Reserve, Yunnan, China. ม.ป.ท.:Mahidol University, 1995. Print.