Sumalai, Kanjana, Piya Supavarasuwat, and Somchai Maunsaiyat. 2019. “AN E-LEARNING LESSON ON BASIC INDOOR ELECTRICITY FOR LEVEL 1 INDOOR ELECTRICIANS”. Journal of Industrial Education 18 (2):188-96. https://ph01.tci-thaijo.org/index.php/JIE/article/view/180665.