VITRYCHENKO, I. E. On stability of the trivial solution of a nonautonomous quasilinear system whose characteristic equation has multiple roots. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 46, n. 8, p. 1072–1079, 1994. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/5660. Acesso em: 5 dec. 2025.