Kurniawan, I. “Design and Build an Expert System in the Diagnosis of Ear, Nose and Throat Diseases by Using the Certainty Factor Method”. Journal of Intelligent Decision Support System (IDSS), vol. 3, no. 2, June 2020, pp. 46-50, https://idss.iocspublisher.org/index.php/jidss/article/view/56.