@InProceedings{HillS00,
  author =       {Hill, Patricia M. and Spoto, Fausto},
  title =        {Analysis of {D}ownward {C}losed {P}roperties of {L}ogic
{P}rograms},
  booktitle =    {Proc.\ of the International Conference on Algebraic
Methodology and Software Technology, AMAST'2000},
  year =         {2000},
  month =        {May},
  address =      {Iowa City, Iowa},
  volume =       {1816},
  pages =        {181--196},
  publisher =    {Springer-Verlag},
  note =         {\copyright Springer-Verlag}