@incollection{Puddu1986,
  author    = {{Susana Puddu}},
  title     = {{The Syracuse problem (Spanish), 5$^{\rm  th}$}},
  booktitle = {{Latin American Colloq. on Algebra -- Santiago 1985}},
  publisher = {{Notas Soc. Math. Chile}},
  year      = {{1986}},
  volume    = {{5}},
  pages     = {{199--200}},
  note      = {{MR88c:11010}},
}