BASRI, N.; INTANAM, N. An Action Research on Development of Mathematic Learning Achievement in the Inequality of Matthayom Suksa 3 Student, Sompoipittayakom School By Problem–based Learning Approach. Ubon Ratchathani Journal of Research and Evaluation, [S. l.], v. 6, n. 1, p. 69–76, 2021. Disponível em: https://so06.tci-thaijo.org/index.php/ubonreseva/article/view/251035. Acesso em: 18 may. 2024.