“Spatial Distribution of the Heavy Metals: Ni, Fe, Cr, and Mn in Roadside Soils of Maiduguri Metropolis, Borno State Nigeria”. Global Journal of Science Frontier Research 14, no. H1 (April 28, 2014): 1–5. Accessed August 14, 2026. https://www.journalofscience.org/index.php/GJSFR/article/view/1275.