Subcritical perturbations of resonant linear problems with sign-changing   potential
  We establish existence and multiplicity theorems for a Dirichlet boundary value problem at resonance, which is a nonlinear subcritical perturbation of a linear eigenvalue problem studied by Cuesta. Our framework includes a sign-changing potential and we locate the solutions by using the Mountain Pass lemma and the Saddle Point theorem. 
Teodora Liliana Dinu (CNFB)