PAPAGEORGIOU, Nikolaos S. and RADULESCU, Vicentiu D. Solutions with sign information for nonlinear nonhomogeneous elliptic equations. Topological Methods in Nonlinear Analysis. Online. 1 June 2015. Vol. 45, no. 2, pp. 575 - 600. [Accessed 3 July 2024]. DOI 10.12775/TMNA.2015.027.