The solution of a Cauchy problem for a degenerate singularly perturbed linear system. Neliniini Kolyvannya, [S. l.], v. 2, n. 3, p. 314–324, 1999. Disponível em: https://twinhead.imath.kiev.ua/index.php/nosc/article/view/66. Acesso em: 22 jan. 2026.