Ismail, Sarah Raad, et al. “Evaluation of Markers CD4+, CD8+, IFN-γ in Male Smokers in Diayla Governorate Iraq”. Diyala Journal of Medicine, vol. 16, no. 1, Mar. 2019, pp. 10-20, https://www.djm.uodiyala.edu.iq/index.php/djm/article/view/196.