Mansur, Dieni, et al. “Sodium Bisulfite As SO3 Source for Synthesis of Methyl Ester Sulfonate Using RBD Stearin As Raw Material”. IPTEK The Journal for Technology and Science, vol. 18, no. 4, June 2025, pp. 116-21, https://journal.its.ac.id/index.php/jts/article/view/5923.