- ↑ 1.0 1.1
"Okapia johnstoni". IUCN Red List of Threatened Species. Version 2012.2. International Union for Conservation of Nature. 2008. Ginkuhà 24 Oktubre 2012.
- ↑ Wilson, Don E., and DeeAnn M. Reeder, eds. (1992) , Mammal Species of the World: A Taxonomic and Geographic Reference, 2nd ed., 3rd printing
- ↑ (1998) , website, Mammal Species of the World
- ↑ Wilson, Don E., and F. Russell Cole (2000) , Common Names of Mammals of the World
- ↑ 5.0 5.1 Bisby F.A., Roskov Y.R., Orrell T.M., Nicolson D., Paglinawan L.E., Bailly N., Kirk P.M., Bourgoin T., Baillargeon G., Ouvrard D. (ed.) (2011). "Species 2000 & ITIS Catalogue of Life: 2011 Annual Checklist". Species 2000: Reading, UK. Ginkuhà 24 Septyembre 2012.CS1 maint: multiple names: authors list (link) CS1 maint: extra text: authors list (link)
- ↑ ITIS: The Integrated Taxonomic Information System. Orrell T. (custodian), 26 Abril 2011
