STARUN, I. I.; SHKII, N. I. Linear Singularly Perturbed Systems. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 54, n. 12, p. 1688–1693, 2002. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/4207. Acesso em: 6 dec. 2025.