1. M. Hisio, T. Ito, Y. Eliada, K. Nagaoka, and Y. Nomiya, Japanese Patent No. 24984 (1970);
2. Ref. Zh. Khim., 19N444P (1971).
3. Soc. Industrielle pour la Fabrication des Antibiotiques, French Patent No. 1365504 (1964);
4. Ref. Zh. Khim., 23N432P (1966).
5. Soc. Industrielle pour la Fabrication des Antibiotiques, French Patent No. 1367604 (1964);