@article{Shi2005b,
  author    = {{Shi, Qian Li}},
  title     = {{Properties of the $3x+1$ problem}},
  journal   = {{J. Yangzte Univ. Natural Science. [Changjiang daxue xuebao. Zi ke ban]}},
  year      = {{2005}},
  volume    = {{2}},
  number    = {{10}},
  pages     = {{287--289}},
  note      = {{MR 2241263}},
}