Zhurnal Russkago Fiziko-Khimicheskago Obshchestva, , vol. 25, p. 154 Chemische Berichte, 26 Ref. <1893>, 58 Journal of the American Chemical Society, , vol. 57, p. 1382 Bulletin des Societes Chimiques Belges, , vol. 46, p. 270,271,272,273