AKBAYIR, Nihat, et al. “A Case Report of Doxycycline Induced Esophageal and Gasric Ulcer”. Turkish Journal of Gastroenterology, vol. 13, no. 4, Jan. 2002, pp. 232-5, https://www.turkjgastroenterol.org/index.php/tjg/article/view/1226.