NÁPOLES VALDÉS, J. E.; NEGRÓN SEGURA, C. On the Behaviour of Solutions of Second Order Linear Differential Equations. Revista Integración, temas de matemáticas, [S. l.], v. 14, n. 2, p. 49–56, 2010. Disponível em: https://revistas.uis.edu.co/index.php/revistaintegracion/article/view/989. Acesso em: 17 may. 2024.