"Assessment of the Environmental Impact of Fly Ash on the Concentration of  Heavy Metals Around Cement Company of Northern Nigeria". Lafia Journal of Scientific and Industrial Research 3, no. 1 (نوفمبر 5, 2024): 7–12. تاريخ الوصول مايو 17, 2026. https://lafiascijournals.org.ng/index.php/ljsir/article/view/370.