@INPROCEEDINGS{jbskw07,
  author = {Toni Jussila and Armin Biere and Carsten Sinz and Daniel Kroening and Christoph M. Wintersteiger},
  title = {A First Step Towards a Unified Proof Checker for {QBF}},
  booktitle = {Proceedings of the Tenth International Conference on Theory and Applications of Satisfiability Testing (SAT 2007)},
  year = {2007},
  number = {4501},
  series = {LNCS},
  publisher = {Springer}
}