1. E. T. Denisov, Izv. Akad, Nauk SSSR, Ser. Khim., No. 7, 1608?1610 (1967).
2. G. T. Sushihashi, S. Miyajmi, T. Otsu, et al., Tetrahedron Lett., 21, 1039?1053 (1965).
3. A. M. Toroptseva, K. V. Belgorodskaya, and V. M. Bondarenko, Laboratory Manual for Chemistry and Technology of Macromolecular Compounds [in Russian], Khimiya, Leningrad (1972).
4. A. J. Gordon and R. A. Ford, The Chemist's Companion, Wiley, New York (1972).
5. F. C. Montgomery, R. W. Larson, and W. R. Richardson, Anal. Chem., 45, No. 13, 154?156 (1973).