1. D. G. Kolesnikov undN. A. Bugrim, Med. Prom. SSSR14, Nr. 2, 19 (1960); Chem. Abstr.54, 21 647 f (1960).
2. T. Reichstein undH. Rosenmund, Pharmac. Acta Helv.15, 150 (1940).
3. D. G. Kolesnikov undN. A. Bugrim, Med. Prom. SSSR14, Nr. 7, 27 (1960); Chem. Abstr.55, 10 801 h (1961).
4. A. Katz undT. Reichstein, Pharmac. Acta Helv.22, 437 (1947).
5. R. Tschesche undR. Petersen, Chem. Ber.86, 574 (1953).