1. A. Simonyi, Gyogyszereszet,7, 430 (1963); Ref. Zh. Khimiya, No. 5, 74 (F965).
2. U.S. Patent No. 3,093,632 (1963)
3. Ref. Zh. Khimiya, No. 6, 51 (1965).
4. U.S. Pat. No. 3,098,066 (1963); Ref. Zh. Khimiya, No. 8, 51 (1965).
5. H. Najer, R. Giudicelli, and J. Sett, Bull. Soc. Chim. France, No. 1, 204 (1965).