1. Efstratiou, A. and George, R., N, Rev. Med. Microbiol., 1996, vol. 7, pp. 31–42.
2. Sharma, N.C., Banavaliker, J.N., Ranjan, R., and Kumar, R., Indian J. Med. Res., 2007, vol. 126, pp. 545–552.
3. Galazka, A.M., Robertson, S.E., and Oblapenko, G.P., J. Epidemiol., 1995, vol. 11, pp. 95–105.
4. Holmes, R.K., J. Infect. Dis., 2000, vol. 181,suppl. l, pp. 56–67.
5. Pappenheimer, A.M., Annu. Rev. Biochem., 1977, vol. 46, pp. 69–94.