@article{Cisło:2011,
  author  = "J. Cisło and S. Kondej",
  title   = "Upper bound for the number of bound states induced by the curvature of singular potential",
  journal = "Reports on Mathematical Physics",
  volume  = "Vol. 68",
  number  = "no 2",
  pages   = "225--240",
  year    = "2011",
}