@inproceedings{krupa-contextual,
  title = {{Contextual Integrity and Privacy Enforcing Norms for Virtual Communities}},
  author = {Krupa, Y. and Vercouter, L.},
  booktitle = {COIN},
  url = {http://yann.krupa.free.fr/pdf/tex_coin.pdf},
  year = {2010},
  pages={150}
}