1. Hippopotamus amphibius;RL Lewison;The IUCN Red List of Threatened Species,2017
2. Eksteen JJ. The determination of acceptable hippo densities in the Crocodile River, outside Kruger National Park. MSc Thesis, University of the Witwatersrand. 1993.
3. Census of the Mara River hippopotamus (Hippopotamus amphibius), southwest Kenya, 1980–1982;EL Karstad;Afr J Ecol,1984
4. Kujirakwinja D. The status and conservation of common hippopotamuses in Virunga National Park, Democratic Republic of Congo. M.Sc. Thesis, University of Cape Town, 2010.
5. The density of Hippopotamus amphibius, Linneaus at Lake Naivasha Kenya;AC Smart;Trop Freshw Biol,1990