Order Primates Author Wilson, Don E. Author Reeder, DeeAnn text 2005 The Johns Hopkins University Press Baltimore Mammal Species of the World: a Taxonomic and Geographic Reference (3 rd Edition), Volume 1 111 184 book chapter 0-8018-8221-4 10.5281/zenodo.7316519 Piliocolobus foai subsp. oustaleti Trouessart 1906 Synonyms: Piliocolobus foai subsp. brunneus (Lönnberg 1919) ; Piliocolobus foai subsp. nigrimanus (Trouessart 1906) ; Piliocolobus foai subsp. powelli (Matschie 1913) ; Piliocolobus foai subsp. schubotzi ( Matschie 1914 ) ; Piliocolobus foai subsp. umbrinus ( Matschie 1914 ) .