โพธิ์วงษ์ สัญญา. “Machine Crystallized Fruit of Discrete Power System”. Vocational Education Central Region Journal 4, no. 2 (December 28, 2020): 6–12. Accessed July 4, 2022. https://so06.tci-thaijo.org/index.php/IVECJournal/article/view/246231.