PERWITASARI, D.; SURYA, E. The Development of Learning Material Using Problem Based Learning to Improve Mathematical Communication Ability of Secondary School Students. International Journal of Sciences: Basic and Applied Research (IJSBAR), [S. l.], v. 33, n. 3, p. 200–207, 2017. Disponível em: https://www.gssrr.org/index.php/JournalOfBasicAndApplied/article/view/7382. Acesso em: 6 may. 2024.