@article{PurBot:01,
  journal = {Analele \c Stiin\c tifice ale Univ. Ovidius Constan\c ta, Ser.
             Math.},
  volume = {IX},
  title = {Indicative propositions},
  author = {Purdea, Ioan and Both, Nicolae},
  year = 2001,
  pages = {89--94},
  number = {1},
}