Groves, C. P. (1967). "Geographic variation in the hoolock or white-browed gibbon (Hylobates hoolock harlan 1834)". Folia Primatologica. 7 (3): 276–283. doi:10.1159/000155125. PMID5626313.
Groves, C. P. (1967). "Geographic variation in the hoolock or white-browed gibbon (Hylobates hoolock harlan 1834)". Folia Primatologica. 7 (3): 276–283. doi:10.1159/000155125. PMID5626313.