@inbook{17988,
  author       = {{Köhler, Sven and Schindelhauer, Christian and Ziegler, Martin}},
  booktitle    = {{Fundamentals of Computation Theory}},
  isbn         = {{9783540281931}},
  issn         = {{0302-9743}},
  title        = {{{On Approximating Real-World Halting Problems}}},
  doi          = {{10.1007/11537311_40}},
  year         = {{2005}},
}

@inbook{17989,
  author       = {{Meer, Klaus and Ziegler, Martin}},
  booktitle    = {{Fundamentals of Computation Theory}},
  isbn         = {{9783540281931}},
  issn         = {{0302-9743}},
  title        = {{{An Explicit Solution to Post’s Problem over the Reals}}},
  doi          = {{10.1007/11537311_41}},
  year         = {{2005}},
}