Sheehan, John C. The enchanted ring : the untold story of penicillin / John C. Sheehan. - Cambridge : MIT Press, 1982. - xvi, 224 p. : ill. ; 22 cm. Includes bibliography and index. Open access. ISBN: 0262192047 LCCN: 822093 Subjects--Topical Terms: Penicillin--History.