Siengdee, K. (2025). The Study on the Impact of Using Supplementary Learning Materials for the Art Learning Area in the Subject of Western Music Education on the Learning Achievement of Grade 2 students at Ramkhamhaeng University Demonstration School (Elementary level). Education journal Faculty of Education, Nakhon Sawan Rajabhat University, 8(3), 46–56. https://doi.org/10.2774.EDU2025.3.277998