Ukpebor, E E, P O Oviasogie, and C A Unuigbe. 2003. “?THE DISTRIBUTION OF Mn, Zn, Cu, Cr, Ni, AND Pb AROUND TWO MAJOR REFUSE DUMPSITES IN BENIN CITY, NIGERIA”. Biological Sciences - PJSIR 46 (6):418-23. https://v2.pjsir.org/index.php/biological-sciences/article/view/1692.