Chaithaisong, N., T. Srisurakul, and P. Boonyuen. “The Development of Additional Lessons Toward the Enhancement of Basic Geometrics Knowledge for 1st grade Students with Learning Disabilities Based on Gagne’s Principle with Multimedia”. Journal Of Ratchasuda Institute for Research and Development of Persons With Disabilities, vol. 20, no. 1, May 2024, pp. 34-49, https://so03.tci-thaijo.org/index.php/RSjournal/article/view/267923.