@article{Matthews2005,
  author    = {{Matthews, Keith R.}},
  title     = {{The generalized $3x+1$ mapping}},
  year      = {{2005}},
  note      = {{preprint, 23pp., dated Oct. 31, 2005, downloadable as pdf file from: http://www.maths.uq.edu.au/$\sim$krm/interests.html}},
}