1. Bowden, F. P., and Scott, H. G., Proc. R. Soc., A258, 268 (1958).
2. Trent, E. M., Proc. R. Soc., A212, 467 (1952).
3. Bowden, F. P., and Tabor, D., Friction and Lubrication of Solids, Part 2, (Oxford Clarendon Press, 1964).
4. Crompton, D., Hirst, W., and Howse, M. G. W., Proc. R. Soc., A333, 435 (1973).
5. Brookes, C. A., and Green, P., Nature phys. Sci., 246, 119–122 (1973).