@article{AlvesGracaDiasRamos2005,
  author    = {{João F. Alves and Mário M. Graca and M. E. Sousa Dias and José Sousa Ramos}},
  title     = {{A linear algebra approach to the conjecture of Collatz}},
  journal   = {{Lin. Alg. Appl.}},
  year      = {{2005}},
  volume    = {{394}},
  pages     = {{277--289}},
  note      = {{MR2100588}},
}