@article{UrataSuzuki1996,
  author    = {{Toshio Urata and Katsufumi Suzuki}},
  title     = {{Collatz Problem}},
  journal   = {{Epsilon (The Bulletin of the Society of Mathematics Education of Aichi Univ. of Education) [Aichi Kyoiku Daigaku Sugaku Kyoiku Gakkai shi]}},
  year      = {{1996}},
  volume    = {{38}},
  pages     = {{123--131}},
}