YANG, Jie, et al. “A Randomized, Double-Blind, Placebo-Controlled Trial to Assess the Essentiality of Acid Inhibitors for Abdominal Pain After Gastroscopic Mucosal Biopsy”. Turkish Journal of Gastroenterology, vol. 24, no. 3, Jan. 2013, pp. 197-03, doi:10.4318/tjg.2013.0556.