Mohammad, Salim Khalid. “The Influence of Tobacco Smoking on the Enzyme Activity of Serum Gamma Glutamyl Transferas (GGT)”. Zanco Journal of Medical Sciences (Zanco J Med Sci) 17, no. 3 (December 1, 2013): 490–494. Accessed June 28, 2022. https://zjms.hmu.edu.krd/index.php/zjms/article/view/349.