@misc{SchmidtSchaussMachkasovaSabel2009,
  author    = {Manfred Schmidt-Schauß and Elena Machkasova and David Sabel},
  title     = {Counterexamples to simulation in non-deterministic call-by-need lambda-calculi with letrec},
  booktitle = {Technical report Frank / Johann-Wolfgang-Goethe-Universit{\"a}t, Fachbereich Informatik und Mathematik, Institut f{\"u}r Informatik ; 38},
  url       = {http://www.ki.informatik.uni-frankfurt.de/papers/schauss/simcounter-IB38.pdf},
  institution = {Informatik},
  series    = {Technical report Frank / Johann-Wolfgang-Goethe-Universit{\"a}t, Fachbereich Informatik und Mathematik, Institut f{\"u}r Informatik},
  number    = {38},
  type      = {workingpaper},
  pages     = {1 -- 10},
  year        = {2009},
}