Okah, R. and Adele, R.C. (2025) “Heavy metals analysis present in lamp black in two major sites of Port-Harcourt Polytechnic Rumuola Port-Harcourt”, Direct Research Journal of Public Health and Environmental Technology, 10(2), pp. 9–11. Available at: https://journals.directresearchpublisher.org/index.php/drjphet/article/view/361 (Accessed: 25 May 2026).