Multiple solutions of $p$-biharmonic equations with Navier boundary   conditions
  In this paper, exploiting variational methods, the existence of multiple weak solutions for a class of elliptic Navier boundary problems involving the $p$-biharmonic operator is investigated. Moreover, a concrete example of an application is presented. 
Giovanni Molica Bisci and Du\v{s}an Repov\v{s}
math.AP