1. Thomas, S. L. S., Turner, H. S., and Wall, W. F., Proc. Inst. Mech. Eng., 182, 271 (1957).
2. Turner, B., thesis, University of Reading (1972).
3. Carder, D. R., thesis, University of Reading (1972).
4. Bassett, D. C., Khalifa, B. A., and Turner, B., Nature Physical Science, 239, 106 (1972).
5. Rees, D. V., thesis, University of Reading (1970).