@inproceedings{Simpson_et_al_2005b,
  title = "Towards fine-grained access control in health grids",
  author = "A. C. Simpson and D. J. Power and M. A. Slaymaker and E. A. Politou",
  year = "2005",
  booktitle = "Proceedings of the Ottawa Workshop on New Challenges in Access Control",
  month = "April",
}