Farooqi, R. J., and M. Z. Afridi. “THE FREQUENCY OF TUBERCULOSIS INFECTION AND TUBERCULIN CONVERSION AMONG HEALTH CARE WORKERS OF KHYBER TEACHING HOSPITAL”. Pakistan Journal of Chest Medicine, vol. 14, no. 3, June 2015, https://www.pjcm.net/index.php/pjcm/article/view/180.