1. Abraham, A. J., and Whiffen, D. H., Trans. Farad. Soc., 54, 1295 (1958).
2. Williams, Dudley, et al., Proc. U.S. Nat. Acad. Sci., 44, 1128 (1958).
3. See, for example, Bovey, F. A., The Effects of Ionising Radiation on Natural and Synthetic High Polymers (Interscience Publishers, New York, 1958).
4. Bailey, A. J., et al., Nature, 190, 259 (1961).
5. Fujimoto, M., and Ingram, D. J. E., Trans. Farad. Soc., 54, 1304 (1958).