Patent Production of oxytetracycline using Streptomyces alboflavus (ATCC 15388) Jan 01, 1972 US 3637463
Patent Polymetaphosphate complexes of .alpha.-6-deoxy-5-hydroxy tetracyclines Jan 01, 1972 DE 2152476
Patent Methacycline and doxycycline from 11a-chloro-6-deoxy-6-demethyl-6-methylenetetracycline Jan 01, 1972 US 3849491