@article{CammarotoChinni1996BPAS,
  author  = {Filippo Cammaroto and Antonia Chinnì},
  title   = {A Complement to Ekeland's Variational Principle in Banach Spaces},
  journal = {Bulletin of the Polish Academy of Sciences. Mathematics},
  volume  = {44},
  number  = {1},
  pages   = {29--33},
  year    = {1996}
}