Kan, Rithy, Thaniya Kaosol, and Perapong Tekasakul. 2016. “Characterization and Elemental Composition of Lignite and Rubber Wood Sawdust Pellets”. Engineering and Applied Science Research 43 (November):259-62. https://ph01.tci-thaijo.org/index.php/easr/article/view/70205.