@article{SimonsWeger2005,
  author    = {{John L. Simons and Benne M. M. de Weger}},
  title     = {{Theoretical and computational bounds for $m$-cycles of the $3n+1$ problem}},
  journal   = {{Acta Arithmetica}},
  year      = {{2005}},
  volume    = {{117}},
  pages     = {{51--70}},
  note      = {{MR 2005h:11049}},
}