1. A. M. Donald andE. J. Kramer,Phil. Mag. A 43 (1981) 857.
2. N. Verheulpen-Heymans, Conference deformation, yield and fracture of polymers, Cambridge, April 1979 (PRI, London, 1979).
3. W. D�ll, L. K�ncz�l andM. G. Schinker,Colloid Polym. Sci. 259 (1981) 171.
4. B. D. Lauterwasser andE. J. Kramer, Microscopic mechanics and mechanics of craze growth and fracture, MSC Report no. 3076.
5. W. W. Wang andE. J. Kramer,J. Mater. Sci. in press.