Howell, C.J.; Begemann, G.J.; Muir, R.W.; Louw, P.; Steyn, P.J.J.; Bigalke, R.D.; Cameron, Colin McKenzie; Gilchrist, Frances M.C.; Morren, A.J.; Verster, Anna J.M.; Verwoerd, Daniel Wynand; Walker, Jane B.
(Published by The Government Printer, Pretoria, 1981)
It was found that the build-up of simuliid numbers subsequent to the construction of dams in the Vaal and Orange Rivers could be successfully prevented by periodic, artificially controlled reductions in the water-levels ...