@article{Simons2008,
  author    = {{John L. Simons}},
  title     = {{On the (non)-existence of $m$-cycles for generalized Syracuse sequences}},
  journal   = {{Acta Arithmetica}},
  year      = {{2008}},
  volume    = {{131}},
  number    = {{3}},
  pages     = {{217--254}},
  note      = {{MR 2008m:11056}},
}