Artamkina, O. B.; Kramarova, E. P.; Shipov, A. G.; Baukov, Yu. I.; Macharashvili, A. A.; et al. Russian Journal of General Chemistry, 1993 , vol. 63, # 10.2 p. 1590 - 1597 Zhurnal Obshchei Khimii, 1993 , vol. 63, # 10 p. 2289 - 2301