Hussain, H., M. Siddiqui, Q. Jamal, M. Aziz, and A. Javaid. “Smoking Cessation by Nicotine Transdermal Patch and Gum: A Review”. Annals of Allied Health Sciences, Vol. 3, no. 2, Dec. 2017, pp. 3-7, http://aahs.kmu.edu.pk/index.php/aahs/article/view/20.