Mfonobong C. Uko, Ubong S. Ukommi, Sunday C. Ekpo, and Rupak Kharel, “Area Spectral Efficiency of a Macro-Femto Heterogeneous Network for Cell-Edge Users under Shadowing and Fading Effects”, ACES Journal, vol. 31, no. 09, pp. 1043–1047, Aug. 2021.