Mawarani, L. J. .; Sihombing, T. A. .; Risanti, D. D. .; Massadeh, M. I. .; Prananto, D. . Utilization of Chicken Eggshells As Catalyst in Biodiesel Synthesis from Waste Cooking Oil: Chicken Eggshells As Catalyst in Biodiesel Synthesis from Waste Cooking Oil. PPASA 2021, 58, 85-95.