Asymptotic properties of solutions of a Cauchy problem for a degenerate singularly perturbed system of differential equations in the case of multiple spectrum of the principal operator. Neliniini Kolyvannya, [S. l.], v. 10, n. 2, p. 247–257, 2007. Disponível em: https://twinhead.imath.kiev.ua/index.php/nosc/article/view/433. Acesso em: 21 jan. 2026.