Landwehr, C.E., "Formal Models for Computer Security," ACM Computing Surveys, 
  Vol. 13, Number 3 (September, 1981).  Also published as NRL Report 8494, 
  September, 1981.  Translated and reprinted in Japanese computer journal 
  ``bit,'' Shuppan Kyoritsu, Tokyo, 1983, No. 1 (January), pp. 95-124.
  [Reprinted in Advances in Computer System Security, Volume II, 
  Rein Turn, Ed., Artech House, Dedham, MA, 1984, pp. 108-122.]
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