Baniviga, Tombari Barimme, Momoh, O.L, Yusuf, and Ibiba Taiwo Horsfall, “Proportional Optimization of Cow Dung and Cow Bone Char for Bioremediation of Crude Oil Polluted Soil”, GJRE, vol. 19, no. J5, pp. 11–21, Mar. 2019.