Development of QR Code Assisted Pop Up Book Based on Problem Based Learning (PBL) for Elementary School Mathematics. Utamax : Journal of Ultimate Research and Trends in Education, [S. l.], v. 8, n. 2, p. 95–109, 2026. DOI: 10.31849/jy829947. Disponível em: https://journal.unilak.ac.id/index.php/UTAMAX/article/view/30385. Acesso em: 9 may. 2026.