Using variational arguments, we prove some nonexistence and multiplicity results for positive solutions of a system of -Laplace equations of gradient form. Then we study a -Laplace-type problem with nonlinear boundary conditions.
"Multiple positive solutions for quasilinear elliptic problems with sign-changing nonlinearities." Abstr. Appl. Anal. 2004 (12) 1047 - 1055, 28 December 2004. https://doi.org/10.1155/S1085337504403078