Linda Wati Batubara, et al. “Efforts to Improve Learning Outcomes in Islamic Religious Education on the Topic of Fasting Through the Problem Posing Method for Fifth Grade Students at SDN 100220 Simaronop, South Tapanuli”. Indonesian Journal of Islamic Education, vol. 1, no. 2, Mar. 2025, pp. 423-8, https://journal.maalahliyah.sch.id/index.php/ijie/article/view/247.