Hassan, Riyadh M., Zuhair B. Kamal, Tawfiq J. Al Marzook, and Wisam A. Hussein. 2010. “Open Access Esophagogastroduodenoscopy”. Journal of the Faculty of Medicine Baghdad 52 (3): 269-73. https://doi.org/10.32007/jfacmedbagdad.523972.