1. Baba, K. (1989). Hitachi Research Co. Ltd, Personal communication.
2. Barnett, M.W. (1988). “Anaerobic Digestion Process Control Using a Knowledge Based System”, PhD Dissertation, Rice University, Houston, Texas.
3. Beck, M.B. (1986). “Identification, Estimation and Control of Biological Wastewater Treatment Processes”, IEE Proceedings, 133:254–264, September.
4. Beck, M.B., A. Latten and R.M. Tong (1978). “Modelling and Operational Control of the Activated Sludge Process in Wastewater Treatment”, Professional Paper PP-78–10, International Institute for Applied Systems Analysis, Laxenburg, Austria.
5. Beck, M.B. (1989). Personal communication.