Yousafzai, M. T., R. Qasim, R. Khalil, M. F. Kakakhel, and S. Rehman. “Hepatitis B Vaccination Among Primary Health Care Workers in Northwest Pakistan”. International Journal of Health Sciences, vol. 8, no. 1, Mar. 2014, https://ijhs.qu.edu.sa/index.php/journal/article/view/725.