● Jennison AV,Verma NK (2004). Shigella flexneri infection: pathogenesis and vaccine development. FEMS Microbiol. Rev.28, 43-58. ● Levine M (1920). Dysentery and allied bacilli. Journal of Infectious Diseases27, 31-39. ● Weldin JC (1927). The colon-typhoid group of bacteria and related forms. Relationships and classification. Iowa State Journal of Science1, 121-197.