Al- Khafaji, K. A., and A. N. Al- Thwami. “Identification of Differences in Virulence Factors Production from Mutant Isolates of Clinical Vibrio Cholerae S”. Journal of Biotechnology Research Center, vol. 5, no. 1, Jan. 2011, pp. 61-73, doi:10.24126/jobrc.2011.5.1.149.