Sherlly, Petronela, Jamil Jamil, and Muhamad Sopyan. “Constraints in The Implementation of Problem-Based Learning in Subject of History in State Senior High School 2 Sendawar”. Yupa: Historical Studies Journal 2, no. 1 (May 31, 2018): 26–32. Accessed April 4, 2025. https://jurnal.fkip.unmul.ac.id/index.php/yupa/article/view/113.