Gottfried, Ted.Alexander Fleming: Discoverer of Penicillin. Franklin Watts, 1997. Provides easy to understand explanations of Fleming's medical procedures. For younger readers.
Kaye, Judith.The Life of Alexander Fleming. Franklin Watts, 1993. A presentation of the man and the 20th century's most outstanding medical discovery. For middle school readers.
Macfarlane, Gwyn.Alexander Fleming: The Man and the Myth. Oxford University Press, 1985. An intriguing study of both Fleming's and Florey's claims as discoverers of penicillin.