จตุรบูรณ์ ศราวุธ, and คุปตัษเฐียร ณฐา. 2014. “Renewable Energy Feasibility Study: Case Study for A Main Telephone Fixed - Line Exchange Unit in Thailand”. Journal of Engineering, RMUTT 1 (June):55-62. https://ph01.tci-thaijo.org/index.php/jermutt/article/view/242076.