Dwi Septa Kariza, R., A. Jamaludin, and A. . Perimajaya. “Expert System Diagnosing Gastroesophageal Reflux Disease (GERD) Using Certainty-Factor Method”. Jurnal Mantik, vol. 6, no. 3, Nov. 2022, pp. 3365-73, https://iocscience.org/ejournal/index.php/mantik/article/view/3130.