N. O. Mmahi, A. Akinbolati, F. N. Ikechiamaka, F. A. Akpaneno, E. Joseph, and K. R. Ekundayo, “STUDIES ON SURFACE RADIO REFRACTIVITY OVER SOME SELECTED CITIES IN NORTH-CENTRAL, NIGERIA”, FJS, vol. 5, no. 4, pp. 90 - 99, Jan. 2022.