@inproceedings{grumberg05proofguided,
  author    = {Orna Grumberg and Flavio Lerda and Ofer Strichman and Michael Theobald},
  title     = {{Proof-Guided Underapproximation-Widening For Multi-Process Systems.}},
  booktitle = {Proc. of the 32nd ACM SIGPLAN-SIGACT Symposium on Principles of
  Programming Languages (POPL)},
  year      = {2005},
  pages     = {122-131},
}