Refernces

Literature cited:

1. Encyclopedia Britanica: Knowledge in Depth. Vol 13 1982

2. W.J. Lewis. Methods For Chemical Analysis of Water and Effluents. May 1987

3. Standard Method for the Examination of Water and Waste Water. 1976

4. Oliver & Lauri

5. Estes, Richard. The Behavioral Ecology of African Mammals.

6. C.H. McFadden & William T. Keeton. Biology: An Exploration of Life WW Norton & Company Inc. 1995

7. R.G. Noble & J.Hemens. 'Inland Water Ecosystems in South Africa - A Review of Research Needed.' South African National Scientific Programmes Report NO. 34. Nov. 1978

8. C.R. Townsens. Studies in Biology No.122 'The Ecology of Streams and Rivers.' Edward Arnold Publishers Ltd. 1980

9. van Rensburg, H.J. Technical note No.19 'Ecology of the Okavango Swamps.' April 1971. Food and Agriculture Organization of the United Nations with the Government of the Republic of Botswana. UNDP (S.F.) Botswana Project 359.