Negara, Chandra Perwira, and Dedi Irawan. “The The Impact of Problem-Based Learning on Students’ Collaboration Skills and Critical Attitudes in History Education”. Journal of Science, Learning Process and Instructional Research, vol. 2, no. 3, Dec. 2024, pp. 34-39, https://journal.riau-edutech.com/index.php/joslepi/article/view/83.