@article{Wu1993,
  author    = {{Wu, Jia Bang}},
  title     = {{On the consecutive positive integers of the same height in the 
Collatz problem}},
  journal   = {{Mathematica  Applicata, suppl. [Ying yung shu hsüeh]}},
  year      = {{1993}},
  pages     = {{150--153}},
  note      = {{MR 1 277 568}},
}