@article{ShallitWilson1991,
  author    = {{Jeffrey  O. Shallit and David W. Wilson}},
  title     = {{The ``$3x+1$'' Problem and Finite Automata}},
  journal   = {{Bulletin of the EATCS (European Association for Theoretical Computer Science)}},
  year      = {{1991}},
  number    = {{46}},
  pages     = {{182--185}},
}