1. National Computer Security Center. Department of defense trusted computer system evaluation criteria. Technical Report DOD 5200.28-STD, Department of Defense, December 1985.
2. B.B. Dillaway and J.T. Haigh. A practical design for a multilevel secure database management system. In Proceedings of the Second Aerospace Computer Security Conference, December 1986.
3. [DLS+87]_D.E. Denning, T.F. Lunt, R.R. Schell, M. Heckman, and W.R. Shockley. A multilevel relational data model. In Proceedings of the 1987 IEEE Symposium on Security and Privacy, April 1987.
4. Technical report;DE Denning,1986
5. P. Dwyer, E. Onuegbe, and B.M. Thuraisingham. Design of a query processor for a multilevel secure relational database management system. Technical report, Honeywell Systems Research Center and Corporate Systems Development Division, 1988.