Pummapanth ืNatteera. “Type of Product : Important Roles to Understand”. Journal of Research and Development Institute Rajabhat Maha Sarakham University 7, no. 1 (June 30, 2020): 303–314. Accessed April 28, 2024. https://so03.tci-thaijo.org/index.php/rdirmu/article/view/237590.