@inproceedings{immlerhoelzl,
  author    = {Fabian Immler and Johannes Hölzl},
  title     = {{Numerical Analysis of Ordinary Differential Equations in Isabelle/HOL}},
  booktitle = {ITP 2012},
  series    = {LNCS},
}
@inproceedings{Immler2014,
  author    = {Fabian Immler and Johannes Hölzl},
  title     = {{Formally Verified Enclosures of Solutions of Ordinary Differential Equations}},
  booktitle = {NASA Formal Methods Symposium 2014},
  series    = {LNCS},
}
@article{Immler2014b,
  author  = {Fabian Immler},
  title   = {Affine Arithmetic},
  journal = {Archive of Formal Proofs},
  month   = Feb,
  year    = 2014,
  note    = {\url{http://afp.sf.net/devel-entries/Affine_Arithmetic.shtml},
            Formal proof development},
  ISSN    = {2150-914x},
}
@Book{walter,
  author =       {Wolfgang Walter},
  title =        {Ordinary Differential Equations},
  publisher =    {Springer},
  year =         {1998},
  edition =      {1},
}

