1. M. W. Darlington andD. W. Saunders, in “Structure and Properties of Oriented Polymers”, edited by I. M. Ward (Wiley, New York, 1975) p. 326.
2. L. Holliday,ibid.“ p. 242.
3. D. W. Hadley,ibid.“ p. 264.
4. H. H. Kausch, in “Polymer Fracture” (Springer-Verlag, Berlin, 1978), Ch. 5.
5. J. C. M. Li, C. A. Pampillo andL. A. Davies, in “Deformation and Fracture of High Polymers”, edited by H. H. Kausch, J. A. Hassell and R. I. Jaffee (Plenum Press, New York, 1973) p. 239.