ลิ้มควรสุวรรณ ว. ., วังใน ช. ., and ชัยประเสริฐ ภ. . “Chracterization of an Anaerobic Baffled- Fixed Film Reactor (ABFFR) in Treating and Producing Biogas From Palm Oil Mill Effluent”. Frontiers in Engineering Innovation Research, vol. 1, June 2010, pp. 49-59, https://ph01.tci-thaijo.org/index.php/jermutt/article/view/242175.