محمد الخيّر, and مجد زيد. “Prevalence of Lung Function Disorder Among Healthcare Workers Who Smoke in Tishreen University Hospital”. Tishreen University Journal -Medical Sciences Series, vol. 44, no. 2, June 2022, pp. 381-93, https://journal.tishreen.edu.sy/index.php/hlthscnc/article/view/12690.