1. Agarwal, A. (1979). Can biogas provide energy for India’s rural poor. Nature, Lond., 281, 9–10
2. Baig, N. and Grenning, E. M. (1976). The use of bacteria to reduce clogging of sewer lines by grease in municipal sewage. In Biological Control of Water Pollution (Eds. Tourbier, J. and Pierson, R. W. Jr.), pp. 245–253. University of Philadelphia Press
3. Benemann, J. R., Wiesman, J. C. and Oswald, W. J. (1979). Algal biomass. In Economic Microbiology, Vol. 4, Microbial Biomass (Ed. Rose, A. H.), pp. 177–206. Academic Press, London
4. Bitton, G., Damron, B. L., Edds, G. T. and Davidson, J. M. (Eds.) (1980). Sludge — Health Risks of Land Application. Ann Arbor Science Publishers
5. Boon, A. G. (1978). Oxygen transfer in the activated sludge process. In New Processes in Waste-water Treatment and Recovery (Ed. Mattock, G.), pp. 17–33. Ellis Horwood, Chichester