On decomposition of a degenerate singularly perturbed linear system of differential equations. Neliniini Kolyvannya, [S. l.], v. 9, n. 3, p. 401–415, 2006. Disponível em: https://nosc.imath.kiev.ua/index.php/nosc/article/view/406. Acesso em: 12 apr. 2026.