1. S. A. Stone, H. C. Wenger, C. T. Ludden, et al., J. Pharmacol. Exp. Ther.,131, 73–84 (1961).
2. B. V. Clineschmidt, H. M. Hanson, J. C. McGuffin, et al., Arch. Int. Pharmacodyn.,223, 283–300 (1976).
3. U. S. Patent No. 1014911 (1969); Chem. Abstr.,56, 10112 (1962).
4. E. D. Engelhardt, H. C. Zell, W. S. Saari, et al., J. Med. Chem.,8, 829–835 (1965).
5. A. Ebnother, E. Jucker, and A. Stoll, Helv. Chim. Acta,48, 1237–1249 (1965).