A $(k, n − k)$ Conjugate Boundary Value Problem with Semipositone Nonlinearity. Communications in Mathematical Research, [S. l.], v. 31, n. 1, p. 51–61, 2021. DOI: 10.13447/j.1674-5647.2015.01.06. Disponível em: https://global-sci.com/index.php/cmr/article/view/8836. Acesso em: 5 dec. 2025.