We study a nonlinear elliptic problem defined in a bounded domain involving biharmonic operator together with an asymptotically linear term. We establish at least three nontrivial solutions using the topological degree theory and the critical groups.
Xingdong Tang. Jihui Zhang. "Multiple Results to Some Biharmonic Problems." Abstr. Appl. Anal. 2014 (SI13) 1 - 6, 2014. https://doi.org/10.1155/2014/267052