Warning - the bibtex entry below may be invalid: 
Missing 'booktitle' field 
@inproceedings{Power_et_al_2009,
  author = "David Power, Mark Slaymaker, and Andrew Simpson",
  journal = "Proceedings of SDM 2009",
  title = "On the construction and verification of self-modifying access control policies",
  year = "2009",
}