1. ?íhalík, J., D. Vavrejnová, J. R??i?ka u. K. Terebová: Chem Listy 49, 693, 1167, 1176, 1731 (1955); 50, 1761, 1768 (1956); 51, 264, 272 (1957); cf. this journal 150, 283 (1956); 153, 311 (1956); 156, 359 (1957); 158, 365 (1957).
2. Gengrinovich A. I.: Farm. ?. 13, (4) 15, 23 (1940); Farmatsiya 10, (2) 23 (1947).
3. Miller, C. O., and N. H. Furman: J. Amer. chem. Soc., 59, 152 (1937).