On a certain singularly perturbed system of ordinary differential quations with a multiple root of the degenerate equation. Neliniini Kolyvannya, [S. l.], v. 21, n. 1, p. 6–28, 2018. Disponível em: https://twinhead.imath.kiev.ua/index.php/nosc/article/view/893. Acesso em: 21 jan. 2026.