Using the Fountain theorem and a version of the Local Linking theorem, we obtain some existence and multiplicity results for a class of fourth-order elliptic equations.
"Existence and Multiplicity of Nontrivial Solutions for a Class of Fourth-Order Elliptic Equations." Abstr. Appl. Anal. 2013 (SI42) 1 - 8, 2013. https://doi.org/10.1155/2013/597193