“Sugarcane Bagasse Biochar As a Solid Catalyst: From Literature Review of Heterogeneous Catalysts for Esterifications to the Experiments for Biodiesel Synthesis from Palm Oil Industry Waste Residue”. 2021. Indonesian Journal of Science and Technology 6 (2): 337-52. https://ijost.upi.edu/index.php/ijost/article/view/302.