@InProceedings{BagnaraZH99,
  Author = "R. Bagnara and E. Zaffanella and P. M. Hill",
  Title = "Enhancing {Sharing} for Precision",
  Pages = "213-227",
  BookTitle = "Proceedings of the
               ``APPIA-GULP-PRODE'99
               Joint Conference on Declarative Programming''",
  Editor = "M. C. Meo and M. Vilares Ferro",
  Address = "L'Aquila, Italy",
  Year = 1999,
}