Kadhem, Maisam A, et al. “Early Detection of Periodontitis Among Young Adult Cigarette Smokers and Non-Smokers Using Cone Beam Computed Tomography ”. Journal of Baghdad College of Dentistry, vol. 26, no. 2, June 2014, pp. 116-21, https://jbcd.uobaghdad.edu.iq/index.php/jbcd/article/view/460.