Phokaruna, A., and Sirisunyaluck, R. “Satisfaction toward on agricultural extension by social media of Phokaruna Co., Ltd. in Chiang Mai province”. International Journal of Agricultural Technology, vol. 11, no. 5, July 2015, pp. 1033-46, https://li04.tci-thaijo.org/index.php/IJAT/article/view/6423.