K.L, T., L. W. Y, and Z. Mohamed. “Single-Strand Conformation Polymorphism Analysis of Variability of the rp0S Sequence in Environmental and Clinical Isolates of Salmonella Typhi”. Malaysian Journal of Science, vol. 20, no. 1, Apr. 2001, pp. 21-25, http://mojes.um.edu.my/index.php/MJS/article/view/8771.