"GEOCHEMICAL APPRAISAL OF OBUDU RANCH SPRING SOUTH -EASTERN NIGERIA" (2021) FULafia Journal of Science and Technology, 7(1), ص 5–12. موجود في: https://lafiascijournals.org.ng/index.php/fjst/article/view/151 (تاريخ الوصول: 17 مايو 2026).