ชำนาญ วิภาดา, and โสธะโร สายัณห์. 2018. “INSTRUCTIONAL ACTIVITY PACKAGE ON LINEAR PROGRAMMING USING A GRAPHIC CALCULATOR FOR MATHAYOMSUKSA FIVE STUDENTS”. Journal of Industrial Education 17 (2):134-42. https://ph01.tci-thaijo.org/index.php/JIE/article/view/119600.