Kareem, Masood A., and Jader A. Jader. “Prevalence of Cigarette and “Waterpipe” Smoking Among ‘Duhok Universities’ Students”. Polytechnic Journal 9, no. 2 (December 1, 2019): 63-69. Accessed September 22, 2020. https://journals.epu.edu.iq/index.php/polytechnic/article/view/24.