1. N. M. Émanuel' and A. L. Buchachenko, Chemical Physics of Aging and Stabilization of Polymers [in Russian], Nauka, Moscow (1982), pp. 44, 215.
2. V. Ya. Shlyapintokh, Photochemical Transformations and Stabilization of Polymers [in Russian], Khimiya, Moscow (1979), p. 27.
3. V. A. Kuz'min, P. P. Levin, and I. V. Khudyakov, Izv. Akad. Nauk SSSR, Ser. Khim., 4000 (1986).
4. F. Wilkinson and A. Garner, Photochem. Photobiol.,27, 659 (1978).
5. A. M. Vasserman and A. L. Kovarskii, Spin Labels and Probes in the Physical Chemistry of Polymers [in Russian], Nauka, Moscow (1986).