Melianingsih, Nuning, and Sugiman Sugiman. “Keefektifan Pendekatan Open-Ended Dan Problem Solving Pada Pembelajaran Bangun Ruang Sisi Datar Di SMP”. Jurnal Riset Pendidikan Matematika 2, no. 2 (November 2, 2015): 211–223. Accessed May 9, 2025. https://journal.uny.ac.id/index.php/jrpm/article/view/7335.