Nwilo, P.C., C.J. Okolie, J.C. Onyegbula, O.E. Abolaji, M.J. Orji, O.E. Daramola, and I.D. Arungwa. “Vertical Accuracy Assessment of 20-Metre SPOT DEM Using Ground Control Points from Lagos and FCT, Nigeria”. Journal of Engineering Research 25, no. 2 (July 27, 2020): 153-164. Accessed October 29, 2020. http://jer.unilag.edu.ng/article/view/997.