1. STONEHAM A.M., HAYES W., SMITH P.H.S. and STOTT J.W., Proc. R. Soc. in press.
2. CAVENETT B.C., HAYES W., HUNTER I.C. and STONEHAM A.M., Proc. R. Soc. in press.
3. BEAUMONT J.H. and HAYES W., Proc. R. Soc. in press.
4. BESSENT R.G., HAYES W., HODBY J.W. and SMITH P.H.S., Proc. R. Soc. in press.