Chantahong, M., Pree-iam, P., & Suikraduang, A. (2021). The Development The Development of problem-based learning activities on price mechanisms in the economy Economics Secondary for Grade 9. Journal for Developing the Social and Community, 8(2), 327–340. retrieved from https://so03.tci-thaijo.org/index.php/rdirmu/article/view/252170