Budyono, Catarina, et al. “Association Between Severity of Dyspepsia and Urea Breath Test Results in Patients With Positive Helicobacter Pylori Serology”. The Indonesian Journal of Gastroenterology, Hepatology, and Digestive Endoscopy, vol. 19, no. 2, July 2020, pp. 79-82, doi:10.24871/192201879-82.