Panigrahi, Saroj, and Sandip Rout. “Existence of Positive Solutions for a Nonlinear Semipositone Boundary Value Problems on a Time Scale”. CUBO, A Mathematical Journal 24, no. 3 (December 21, 2022): 413–437. Accessed April 20, 2024. https://cubo.ufro.cl/ojs/index.php/cubo/article/view/3207.