Nyaluke, K.W, N.B Okelo, and O Ongati. “Orthogonal Idempotents and Continuous Fredholm Operators under Perturbations”. International Journal of Modern Computation, Information and Communication Technology 3, no. 5 & 6 (June 13, 2020): 42–47. Accessed October 22, 2025. https://gjpublications.com/index.php/IJMCICT/article/view/54.