khankaw, Thongjul. “The development of an e-mail newsletter system for the web site of the central regional institute for non-formal and informal (Thai)”. Asia-Pacific Journal of Science and Technology 13, no. 11 (April 19, 2017): 1288–1297. accessed April 22, 2026. https://so01.tci-thaijo.org/index.php/APST/article/view/83487.