Phruksaphithak, Nantharat, Anuwat Sukthong, Warintorn Muanpannarai, and Atima Theptong. “Effect of Ammonium Sulfate on the Porous Creating of Regenerated Cellulose Hydrogel from Palm Oil Trunk”. Science & Technology Asia 24, no. 2 (May 23, 2019): 6-14. Accessed September 26, 2020. https://ph02.tci-thaijo.org/index.php/SciTechAsia/article/view/190603.