@InProceedings{SACACM04,
  author = "H. Macia and V. Valero and F. Cuartero",
  title = "Defining Equivalence Relations in sPBC",
  booktitle = "Proceedings of First International Conference on the Principles of Software Engineering( PriSE2004)",
  address =  {Buenos Aires (Argentina)},
  date =    {November},
  year=   "2004",
  pages= "195-205",
 }