Akma, Tio, and Supar man. “The Design of Student Worksheet Problem Based Learning to Improve Problem Solving Ability of the Eighth-Grade Students Junior High School in Indonesia”. International Journal of Engineering & Technology 7, no. 4.30 (November 30, 2018): 11–15. Accessed May 4, 2024. https://www.sciencepubco.com/index.php/ijet/article/view/21993.