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, [S. l.], v. 56, n. 6, p. 252–274, 2024. Disponível em: https://pujm.pu.edu.pk/index.php/pujm/article/view/149. Acesso em: 28 jun. 2025.