Sampattagul, S., P. Nutongkaew, and T. Kiatsiriroat. “Life Cycle Assessment of Palm Oil Biodiesel Production in Thailand”. Journal of Renewable Energy and Smart Grid Technology, vol. 6, no. 1, Dec. 2014, pp. 1-14, https://ph01.tci-thaijo.org/index.php/RAST/article/view/26175.