VITRYCHENKO, I. E. On stability of annth-order equation in a critical case. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 47, n. 8, p. 1138–1143, 1995. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/5511. Acesso em: 5 dec. 2025.