Obahiagbon, K., and D. O. Ahonkhai. “Optimized Biodiesel Production from Waste Cooking Oil Using Nickel (II) Nitrate Doped Chicken Manure As Catalyst”. European Journal of Applied Sciences, vol. 11, no. 3, July 2023, pp. 812-24, doi:10.14738/aivp.113.14891.