1. Actinomycete scum problems in activated sludge plants;Blackall,1986
2. A survey of bulking and foaming in activated sludge plants in South Africa;Blackbeard;Wat. Pollut. Control,1986
3. Identification of filamentous organisms in nutrient removal activated sludge plants in South Africa;Blackbeard;Wat. S.A.,1988
4. Ecological Aspects of Used-Water Treatment;Curds,1983