@article{WuHuang2001b,
  author    = {{Wu, Jia Bang and Huang, Guo Lin}},
  title     = {{Elongate iteration for the $3N+1$ Conjecture}},
  journal   = {{J. Huazhong Univ. Sci. Tech.}},
  year      = {{2001}},
  volume    = {{29}},
  number    = {{2}},
  pages     = {{112--114}},
  note      = {{MR 1887558}},
}