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