@article{Kisielewicz:1975,
  author  = "M. Kisielewicz",
  title   = "Differentiability of solutions of hereditary differential equations",
  journal = "Discussiones Mathematicae",
  volume  = "T. 21",
  number  = "z. 1",
  pages   = "31--42",
  year    = "1975",
}