Karkarna, Mustapha Z., Yusuf A. Yusuf, and Lawrence F. Umar. “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 April 4, 2025. https://fjs.fudutsinma.edu.ng/index.php/fjs/article/view/56.