@TechReport{bauer+:languagetr,
  author = 	 {Lujo Bauer and Jarred Ligatti and David Walker},
  title = 	 {A Calculus for Composing Security Policies},
  institution =  {Princeton University},
  month =        aug,
  year = 	 {2002},
  number = 	 {TR-655-02},
  url =          {http://www.ece.cmu.edu/~lbauer/papers/languagetr.pdf},
}