VITRYCHENKO, I. E. Critical Cases of the π-Stability of a Nonautonomous Quasilinear Equation of the nth Order. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 56, n. 2, p. 264–270, 2004. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/3750. Acesso em: 6 dec. 2025.