DOĞAN, Ümit Bilge, et al. “The Type and Localization of Gastritis in Patients With Dudenal Ulcer and Relationship to Helicobacter Pylori”. Turkish Journal of Gastroenterology, vol. 9, no. 2, Jan. 1998, pp. 167-71, https://www.turkjgastroenterol.org/index.php/tjg/article/view/881.