NÁPOLES VALDÉS, J. E. On the Ultimate Boundedness of Solutions of Systems of Differential Equations. Revista Integración, temas de matemáticas, [S. l.], v. 13, n. 1, p. 41–47, 1995. Disponível em: https://revistas.uis.edu.co/index.php/revistaintegracion/article/view/1014. Acesso em: 4 jul. 2024.