Helwani Z, Amraini SZ, Asmura J, Siregar TN, Triwahyuni VE, Abd AA. Palm Frond Waste as a Carbon Source in the Synthesis of CaO/Biochar Catalysts for the Biodiesel Production Process. Heca J. Appl. Sci. [Internet]. 2023 Jun. 7 [cited 2026 Apr. 23];1(1):8-13. Available from: https://heca-analitika.com/hjas/article/view/9