1. N. C. Billingham, D. C. Bott and A.S. Manke, Developments in Polymer Degradation, Part 3 (Editor: N. Grassie), Applied Science Publishers, London, 1981, p. 64.
2. W.W. Wright, ibid., p. 1.
3. C. B. Murphy, J. Polym. Sci., 28 (1958) 447.
4. C. F. Cullis and D. J. Smith, Trans. J. Plast. Inst., (1967) 35.
5. P. D. Garn, Treatise Coatings-2, Part 1 (Editor: R. R. Myers), Marcel Dekker, New York, 1960, p. 271.