Yandovskii, V.N.; Dobrodumova, E.Yu.; Tselinskii, I.V. Journal of Organic Chemistry USSR (English Translation), 1980 , vol. 16, # 5 p. 813 - 816 Zhurnal Organicheskoi Khimii, 1980 , vol. 16, # 5 p. 933 - 936