@ARTICLE{letraon06a,
  author = {Le~Traon, Yves and Baudry, Benoit and J\'ez\'equel, Jean-Marc},
  title = {Design by Contract to improve Software Vigilance},
  journal = {IEEE Transactions on Software Engineering},
  year = {2006},
  volume = {32},
  pages = {571--586},
  number = {8},
  month = aug
}