@article{CFGPR97,
  author = {A. Cortesi and G. Fil\'e and R. Giacobazzi and 
            C. Palamidessi and F. Ranzato},
  title = {Complementation in Abstract Interpretation},
  year = {1997},
  journal = "ACM Transactions on Programming Languages and Systems",
  volume={19},
  number= {1},
  pages = {7-47}}