“Characteristic Levels of Total Petroleum Hydrocarbons in Soil, Sediment and Surface Water of an Oil Impacted Area in the Niger Delta”. Biological Sciences - PJSIR 50, no. 4 (August 9, 2007): 247–250. Accessed March 15, 2026. https://v2.pjsir.org/index.php/biological-sciences/article/view/973.