1. W. Reppe, Annalen,601, 81 (1956).
2. G. S. Kolesnikov, Synthesis of Vinyl Derivatives of Aromatic and Heterocyclic Compounds [in Russian], Izd. Akad. Nauk SSSR, Moscow (1960).
3. P. Vatsulik, The Chemistry of Polymers [in Russian], Vol. I. IL Moscow (1960).
4. W F. Shostakovskii, G. G. Skvortsova, and E. S. Domnina, Uup. Khim.,38, 892 (1969).
5. F. P. Sidel'kovskaya, The Chemistry of N-Vinylpyrrolidone and Irs Polymers [in Russian], Nauka, Moscow (1970).