@techreport{UNITYunreachability,
  title = "{Translating CSP trace refinement to UNITY unreachability : a study in data independence}",
  author = "A. W. Roscoe and Xu Wang and R.S. Lazic",
  year = "2003",
  institution = "Oxford University Computing Laboratory",
  month = "April",
  number = "RR-03-08",
  url = "http://web.comlab.ox.ac.uk/oucl/work/bill.roscoe/publications/93.ps",
}