NURBAITI; SRI REZEKI. DEVELOPMENT OF MATHEMATICS LEARNING DEVICES WITH PROBLEM BASED LEARNING (PBL) MODELS ON MATERIALS FOR CONSTRUCTING FLAT SIDE SPACE . Mathematics Research and Education Journal, [S. l.], v. 5, n. 1, 2021. DOI: 10.25299/mrej.2021.vol5(1).9211. Disponível em: https://journal.uir.ac.id/index.php/JPM/article/view/9211. Acesso em: 21 jul. 2026.