“Existence and Ulam Stability of First Order Nonsingular Impulsive and Delay Integrodifferential System Using a Concept of the Delayed Matrix Exponential”. Punjab University Journal of Mathematics 56, no. 6 (June 2, 2024): 252–274. Accessed June 28, 2025. https://pujm.pu.edu.pk/index.php/pujm/article/view/149.