Schmidt,M.; Siebert,W. Angewandte Chemie, 1966 , vol. 78, p. 607 Full Text Show Details Schmidt, M.; Rittig, F. R.; Siebert, W. Z. Naturforsch. b, 1970 , vol. 25, p. 1344 - 1347 Full Text Show Details Gmelin Handbook: B: B-Verb.3, 2.9.2, page 38 - 40