We study a class of resonant cooperative elliptic systems and replace the Ambrosetti-Rabinowitz superlinear condition with general superlinear conditions. We obtain ground state solutions and infinitely many nontrivial solutions of this system by a generalized Nehari manifold method developed recently by Szulkin and Weth.
"Infinitely Many Nontrivial Solutions of Resonant Cooperative Elliptic Systems with Superlinear Terms." Abstr. Appl. Anal. 2014 (SI71) 1 - 8, 2014. https://doi.org/10.1155/2014/349304