Abd Ala, Isra A., et al. “Detection of Chronic Obstructive Pulmonary Disease Among Smokers Aged ≥40 Years Attending Primary Health Care Centers in Baghdad-AL-Karkh and AL-Resafa”. Journal of the Faculty of Medicine Baghdad, vol. 64, no. 4, Jan. 2023, pp. 245-51, https://doi.org/10.32007/jfacmedbagdad.6441936.