Chinda, B., and Yunus, M.M. “Investigation on Pesticide Residue Levels and Heavy Metal Concentrations in Zea-Mays and Oryza Sativa Grains in Biu Area”. International Journal of Science for Global Sustainability 5, no. 1 (September 30, 2019): 7. Accessed October 4, 2025. https://www.fugus-ijsgs.com.ng/index.php/ijsgs/article/view/157.