G.T, Akpabio, Udoinyang I.E, and Basil T.S. 2017. “Effect of Used Motor Oil Contamination on Geotechnical Properties of Clay Soil on Uyo-Akwa Ibom”. International Journal of Natural Sciences Research 5 (2):22-30. https://doi.org/10.18488/journal.63.2017.52.22.30.