1. Hill, R., The Mathematical Theory of Plasticity, ch. X, p. 262, Oxford University Press, London (1950)
2. Shield, R. T., On the plastic flow of metals under conditions of axial symmetry, Proc. R. Soc. (A), 233, 267 (1955)
3. Hill, R., Ideal forming operations for perfectly plastic solids, J. Mech. Phys. Solids, 15, 223 (1967)
4. Richmond, O. and Morrison, H. L., Streamlined wire drawing dies of minimum length, J. Mech. Phys. Solids, 15, 195 (1967)
5. Haar, A. and von Karman, T., Zur Theorie der Spannungszustände in plastischen und sandartigen Medien, Nachr. Ges. Wiss. Göttingen, 204 (1909)