Samuel, Jefry, Tan Hian Nio, and Kerdid Simbolon. “The Effect of Numbered Head Together Learning Model Assisted by Learner Worksheets on Mathematical Problem-Solving Ability”. EduMatSains : Jurnal Pendidikan, Matematika dan Sains 10, no. 2 (October 31, 2025): 1–14. Accessed April 28, 2026. https://ejournal.uki.ac.id/index.php/edumatsains/article/view/7011.