1. S.Chakravarthy, U. Goldberg, O. Peroomian andB. Sekar, "Some Algorithmic Issues in Viscous Flows Explored using a Unified-Grid CFD Methodology", AIAAPaper 97-1944.
2. Giles "Non-Reflective Boundary Conditions for EulerEquationCalculations", AIAAPaper 89-1942
3. L. Atikins and J. Casper "Non-Reflective Boundary Conditions for High-Order Methods", AIAA Paper 93-0152.