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://twinhead.imath.kiev.ua/index.php/nosc/article/view/406. Acesso em: 21 jan. 2026.