Purnamasari, Yessy, Sri Mujiyono, and Fiktina Ismiriyam. “Expert System for The Diagnosis of Depression in Students Using Certainty Factor Method: A Case Study of Ngudi Waluyo University”. Journal of Information Systems and Informatics 7, no. 1 (March 30, 2025): 909-923. Accessed December 20, 2025. https://journal-isi.org.adsii.or.id/index.php/isi/article/view/950.