HIPPOPOTAMUSАрхив на оригинала от 2008-11-20 в Wayback Machine., Rowan B. Martin, The Transboundary Mammal Project of the Ministry of Environment and Tourism, Namibia facilitated by The Namibia Nature Foundation, July 2005
HIPPOPOTAMUSАрхив на оригинала от 2008-11-20 в Wayback Machine., Rowan B. Martin, The Transboundary Mammal Project of the Ministry of Environment and Tourism, Namibia facilitated by The Namibia Nature Foundation, July 2005