NDUKA, J. O., and A. O. AIGBERUA. “Heavy Metals and Physicochemical Characteristics of Soils from the Banks of Effluent Wastewater Retention Pits in the Niger Delta, Nigeria”. Biotechnological Research, Vol. 4, no. 1, Mar. 2018, pp. 48-53, doi:10.15419/br.v4i1.766.