Youcef, Ziad, Kamal Bachouche, and Toufik Moussaoui. 2024. “Existence of Nonnegative Solution for a Boundary Value Problem via Upper and Lower Method on the Half-Line”. Proyecciones (Antofagasta, On Line) 43 (3):665-82. https://doi.org/10.22199/issn.0717-6279-5202.