VILJOEN, P.J. The distribution and population status of the larger mammals in Kaokoland, South West Africa/Namibia. - Windhoek, 1982.
UNITED NATIONS INSTITUTE FOR NAMIBIA (UNIN)
UNITED NATIONS INSTITUTE FOR NAMIBIA (UNIN)
http://192.168.151.11//viljoen-p-j-distribution-and-population-status-of-larger-mammals-in-kaokoland-south-west-africa-namibia-windhoek-1982
PA 4/1/1/415(NAM 639.97909688 Vil)