Hybrid CaO/ZnFe2O4 Modified with Al2O3 as a Green Catalyst for Biodiesel Production from Waste Cooking Oil. Valensi [Internet]. 2024 May 31 [cited 2025 Oct. 9];10(1):1-10. Available from: https://journal.uinjkt.ac.id/index.php/valensi/article/view/36594