1. P. R. Hayes, T. A. McMeekin and J. M. Shewan, “Identification Methods for Microbiologists,” 2nd Ed., Academic Press, London-New York, 1979, p. 177.
2. A. C. Baird-Parker, “Identification Methods for Microbiologists,” 2nd Ed., Academic Press, London-New York, 1979, p. 201.