AIGBERUA, A. O., A. T. EKUBO, A. K. INENGITE, and S. C. IZAH. “Seasonal Variation of Nutrient Composition in an Oil Spill Contaminated Soil: A Case of Rumuolukwu, Eneka, Port Harcourt, Nigeria”. Biotechnological Research, Vol. 2, no. 4, Dec. 2016, pp. 179-86, http://br.biomedpress.org/index.php/br/article/view/733.