@Misc{ 
  Has12a,
  author = { Hassannezhad, Asma },
  title = { Eigenvalues of perturbed Laplace operators on compact manifolds },
  journal = {  },
  year = { 2012 },
  pages = {  },
  URL = { http://cvgmt.sns.it/paper/4936/ },
  note = { cvgmt preprint}
}