REFERENCES
- BOWNS , D. E. , 1970 , Internal Report of the School of Engineering , Bath University of Technology . Paper to he published in Proc. I. Mech.E .
- FLOWER , J. O. , and HAZELL , P. A. , 1971 , Int. J. Control , 13 , 609 .
- HAZELL , P. A. , and FLOWER , J. O. , 1971 , Int. J. Control , 13 , 625 .
- †Communicated by Professor J. C. West.