Hasni, K., A. Nabi, M. Varman, and Z. Ilham. 2021. “Preparation of Biodiesel from Hibiscus Sabdariffa Seeds Oil Using Calcium Oxide Catalyst from Waste Egg Shells”. Journal of the Society of Automotive Engineers Malaysia 2 (2). Kuala Lumpur, Malaysia:177-83. https://doi.org/10.56381/jsaem.v2i2.83.