@incollection{Conway1987,
  author    = {{John H. Conway}},
  title     = {{FRACTRAN- A Simple Universal Computing Language for Arithmetic}},
  booktitle = {{Open Problems in Communication and Computation}},
  publisher = {{Springer-Verlag}},
  year      = {{1987}},
  pages     = {{3--27}},
  note      = {{MR 89c:94003}},
}