“THE IMPACT OF SURFACE BLUE SAPPHIRE MINING ON LAND USE LAND COVER TYPES IN THE MAMBILA PLATEAU”, FJS, vol. 4, no. 1, pp. 355–370, Apr. 2020, Accessed: Sep. 12, 2025. [Online]. Available: http://www.fjsadmin.fudutsinma.edu.ng/index.php/fjs/article/view/56