Abdalilah Alhalangy, Osman Abdalla Mohamed Elhadi, and Eslam Hassan Gorshi Mohamed. “E-Learning Effectiveness and Efficiency in Kassala and Gedaref Universities: An IS-Impact Evaluation”. Utilitas Mathematica, vol. 122, no. 2, Sept. 2025, pp. 1301-17, https://utilitasmathematica.com/index.php/Index/article/view/2859.