Effectiveness of Android-Based Learning Media “Teman Ritma” to Improve Problem-Solving Skills of SMP Negeri 5 Yogyakarta. Jurnal Mercumatika : Jurnal Penelitian Matematika dan Pendidikan Matematika, [S. l.], v. 6, n. 2, 2022. DOI: 10.26486/jm.v6i2.2447. Disponível em: https://ejurnal.mercubuana-yogya.ac.id/index.php/mercumatika/article/view/2447. Acesso em: 30 jun. 2026.