@Article{ 
  amagia06,
  author = { Amar, Micol and Berrone, Lucio R. and Gianni, Roberto },
  title = { A non local quantitative characterization of ellipses leading to a solvable differential relation },
  journal = { J. Inequal. in Pure & Appl. Math. },
  year = { 2008 },
  volume = { 9 },
  number = { 4 },
  pages = { 14 pp. },
  URL = { http://cvgmt.sns.it/paper/1498/ },
  note = { cvgmt preprint}
}