Chumnuan, P., and N. Chaimongkol. “Effects of The Feedback Applying Code Program on Problem Solving Skills Development of Elementary School Students”. Journal of Education Studies, vol. 50, no. 1, Mar. 2022, p. EDUCU5001006 (9 pages) doi: 10.14456/educu.2022.6, https://so02.tci-thaijo.org/index.php/EDUCU/article/view/255021.