J Bacteriol. 1944 Dec;48(6):639-59.
Penicillin: II. Natural Variation and Penicillin Production in Penicillium notatum and Allied Species.
Raper KB, Alexander DF, Coghill RD.
Fermentation Division, Northern Regional Research Laboratory, Peoria, Illinois.
PMID: 16560880 [PubMed]
PMCID: 374019