1. Chang, T. M., J. Inst. Met.78 (1950) 393.
2. Chang, T. M. and H. W. Swift, J. Inst. Met.78 (1950) 119.
3. Hill, R., E. H. Lee, and S. J. Tupper, Proc. Roy. Soc. A.188 (1947) 273.
4. Hill, R., J. Mech. and Phys. of Solids1 (1953) 265.
5. Hill, R., Mathematical Theory of Plasticity, Clarendon Press, Oxford, 1950.