MANGALAGOWRI.R. Positive Solutions for Higher-Order Boundary Value Problems. International Journal of Engineering and Management Research, [S. l.], v. 5, n. 4, p. 509–517, 2015. Disponível em: https://ijemr.vandanapublications.com/index.php/ijemr/article/view/699. Acesso em: 3 jul. 2024.