Bulletin de la Societe Chimique de France, , p. 1083,1085 Zhurnal Obshchei Khimii, , vol. 27, p. 997,1001; engl. Ausg. S. 1079, 1082 Journal of the American Chemical Society, , vol. 75, p. 6329 Journal of the Chemical Society, , p. 4967,4969