N. L Nwakwasi, B. U Dike, A. N. Nwachukwu, H. U. Nwoke, and J. C. Agunwamba, “Prediction of Soil Nitrogen Depeltion in Crude Oil Contaminated Soil in Southern Nigeria”, GJRE, vol. 20, no. E1, pp. 7–12, Jan. 2020.