@article{BlazewitzPettorossi1983,
  author    = {{Jacek Bł ażewitz and Alberto Pettorossi}},
  title     = {{Some properties of binary sequences useful for proving Collatz's conjecture}},
  journal   = {{J. Found. Control Engr.}},
  year      = {{1983}},
  volume    = {{8}},
  pages     = {{53--63}},
  note      = {{MR 85e:11010, Zbl. 547.10000}},
}