Modhuang, C., and K. Kamchai. “9Ps Model Affecting to the Consumer’s Behavior of Local Brand Coffee Consumers in Muang District, Chiangmai Province”. RMUTL Journal of Business Administration and Liberal Arts, vol. 6, no. 1, May 2018, pp. 32-40, https://so05.tci-thaijo.org/index.php/balajhss/article/view/125982.