Kan, Rithy, Thaniya Kaosol, and Perapong Tekasakul. “Characterization and elemental composition of lignite and rubber wood sawdust pellets”. Engineering and Applied Science Research 43 (November 2, 2016): 259–262. accessed September 23, 2026. https://ph01.tci-thaijo.org/index.php/easr/article/view/70205.