Zhurnal Russkago Fiziko-Khimicheskago Obshchestva, , vol. 23, p. 185 Chemische Berichte, , vol. 24, p. Ref.,668 Zhurnal Russkago Fiziko-Khimicheskago Obshchestva, , vol. 25, p. 309 Journal fuer Praktische Chemie (Leipzig), , vol. <2>51, p. 534