James, M Okuo, and P O Okolo. 2003. “?VARIATION OF HEAVY METAL CONCENTRATIONS IN WATER AND FRESHWATER FISH IN NIGER DELTA WATERS - A CASE STUDY OF BENIN RIVER”. Biological Sciences - PJSIR 46 (6):439-42. https://v2.pjsir.org/index.php/biological-sciences/article/view/1697.