Adam, D., M. Ali, M. Ahmed, A. Banaga, A. Alrahman, and E. Alzain. “HIGHLIGHTS ON THE HISTORY OF SMALLPOX EPIDEMIOLOGY AND ERADICATION IN THE SUDAN”. International Journal of Research -GRANTHAALAYAH, vol. 3, no. 6, June 2015, pp. 128-36, doi:10.29121/granthaalayah.v3.i6.2015.3008.