Kinasih T, Ratnawati N. The effectiveness of the project based learning model in improving students’ collaboration skills on creative economic materials. JTP2IPS [Internet]. 2025 Jul. 17 [cited 2026 Jun. 4];9(1):1-13. Available from: https://journal-fis.um.ac.id/index.php/jtp2ips/article/view/1019