Chanmarlee, B., พานทอง ก., and P. Pradujprom. “Enhancing Math Problem Solving Skills and Working Memory of Grade 3 Students using a Problem-based Learning Method Together with the Application of Abstract Code Model”. Journal of MCU Phetchaburi Review, vol. 7, no. 1, Apr. 2024, pp. หน้า 486 - 503, https://so03.tci-thaijo.org/index.php/JPR/article/view/275275.