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The rivers of Northern Natal and Zululand : [von] C. G. M. Archibald; O. J. Coetzee [u.a.]
Archibald, C. G. M., (1969)
Water quality and abatement of pollution in Natal rivers
(1967)
Objectives of river surveys, description of methods used and discussion of water quality criteria : [von] P. A. J. Brand; P. H. Kemp [u.a.]
Brand, P. A. J., (1967)