@article{Kisielewicz:1983,
  author  = "M. Kisielewicz and L. Rybiński",
  title   = "Generalized fixed point theorem",
  journal = "Demonstratio Mathematica",
  volume  = "Vol. 16",
  number  = "no 4",
  pages   = "1037--1041",
  year    = "1983",
}