Ahmed Memon, Ashfaq, Muhammad Ayaz Mustufa, and Muhammad Ashfaq. 2010. “Frequency of Smoking Among Employees at a Tertiary Care Children Hospital, Karachi”. Journal of the Dow University of Health Sciences (JDUHS) 4 (1):43-46. https://jduhs.com/index.php/jduhs/article/view/1293.