Firdaus, Alfa, Machfud Machfud, Ani Suryani, and Noer Azam Achsani. 2019. “Measuring Indonesia’s Energy Security Level in the Context of Biodiesel Agroindustry”. International Journal of Energy Economics and Policy 9 (6):154-64. https://www.econjournals.com/index.php/ijeep/article/view/8255.