P. Teweerum, K. Sringan, and B. Wannupatam, “The Development of Learning Achievement and the Ability to Solve Mathematical Problems regarding fractions by Using Polya’s Problem Solving Concept with Bar Model for Grade 3 Students: The Development of Learning Achievement and the Ability to Solve Mathematical Problems regarding fractions by Using Polya’s Problem Solving Concept with Bar Model for Grade 3 Students”, rtnb, vol. 7, no. 3, pp. 143–155, Dec. 2025.