1. Doraivelu, S. M., H. L. Gegel, J. S. Gunasekera, J. C. Malas, J. T. Morgan and J. F. Thomas, Jr., (1984). A new yield function for compressible P/M materials. Private communication.
2. Application of a forming limit concept to the design of powder preforms for forging;Downey;J. Eng. Mat. Tech.,1975
3. A plasticity theory for porous solids;Green;Int. J. Mech. Sci.,1972
4. The Mathematical Theory of Plasticity;Hill,1950
5. Engineering Plasticity;Johnson,1980