1. S. A. Shevelev, V. V. Semenov, and A. A. Fainzil'berg, Izv. Akad. Nauk SSSR, Ser. Khim., 2032 (1976).
2. S. A. Shevelev, V. V. Semenov, and A. A. Fainzil'berg, Izv. Akad. Nauk SSSR, Ser. Khim., 139 (1977).
3. S. A. Shevelev, V. V. Semenov, and A. A. Fainzil'berg, Izv. Akad. Nauk SSSR, Ser. Khim., 2530 (1977).
4. D. Lloyd and M. Singer, Chem. Commun., 390 (1967).
5. E. Ernstbrunner and D. Lloyd, Lieb. Ann. Chem.,753, 196 (1971).