“THE IMPACT OF SURFACE BLUE SAPPHIRE MINING ON LAND USE LAND COVER TYPES IN THE MAMBILA PLATEAU”. FUDMA JOURNAL OF SCIENCES 4, no. 1 (April 14, 2020): 355–370. Accessed September 11, 2025. https://fjs.fudutsinma.edu.ng/index.php/fjs/article/view/56.