Colyn, M.; Gautier-Hion, A.; Vanden Audenaerde, D. T. (1991). "Cercopithecus dryas Schwarz 1932 and C. salongo Vanden Audenaerde, Thys 1977 are the same species with an age-related coat pattern". Folia Primatologica. 56 (3): 167–170. doi:10.1159/000156543. PMID1885114.
Colyn, M.; Gautier-Hion, A.; Vanden Audenaerde, D. T. (1991). "Cercopithecus dryas Schwarz 1932 and C. salongo Vanden Audenaerde, Thys 1977 are the same species with an age-related coat pattern". Folia Primatologica. 56 (3): 167–170. doi:10.1159/000156543. PMID1885114.