The following publications are possibly variants of this publication:
- The Extended Schematic Protection ModelPaul Ammann, Ravi S. Sandhu. jcs, 1(3-4):335-384, 1992.
- The Demand Operation in the Schematic Protection ModelRavi S. Sandhu. ipl, 32(4):213-219, 1989.
- A distributed implementation of the extended schematic protection modelPaul Ammann, Ravi S. Sandhu, Gurpreet S. Suri. acsac 1991: 152-164 [doi]
- Safety Analysis for the Extended Schematic Protection ModelPaul Ammann, Ravi S. Sandhu. sp 1991: 87-97
- Expressive Power of the Schematic Protection ModelRavi S. Sandhu. csfw 1988: 188-193
- Expressive Power of the Schematic Protection ModelRavi S. Sandhu. jcs, 1(1):59-98, 1992.