Corncob-Derived Sulfonated Magnetic Solid Catalyst Synthesis as Heterogeneous Catalyst in The Esterification of Waste Cooking Oil and Bibliometric Analysis. Indones. j. sci. technol. [Internet]. 2024 Apr. 1 [cited 2026 Jun. 7];9(1):109-24. Available from: https://ijost.upi.edu/index.php/ijost/article/view/399