Nonlinear differential equations with quasinilpotent operator and unstable zero solution. Neliniini Kolyvannya, [S. l.], v. 8, n. 3, p. 404–414, 2005. Disponível em: https://twinhead.imath.kiev.ua/index.php/nosc/article/view/363. Acesso em: 22 jan. 2026.