Afrouzi, G. A., and S. H. Rasouli. “On Positive Solutions for Some Nonlinear Semipositone Elliptic Boundary Value”. Nonlinear Analysis: Modelling and Control 11, no. 4 (November 1, 2006): 323–329. Accessed April 20, 2025. https://www.zurnalai.vu.lt/nonlinear-analysis/article/view/14736.