1. R. A. C. Slater, Engineering Plasticity, John Wiley, New York, 1977
2. C. L. Dym and I. H. Shames, Solid Mechanics. A Variational Approach, McGraw-Hill, New York, 1973
3. A variational principle for a state of combined plastic stress
4. L. M. Kachanov, Fundamentals of the Theory of Plasticity (Translated from the Russian by M. Konyaeva) Mir Publishers, Moscow, 1974
5. P.-C. Chou and N. J. Pagano, Elasticity: Tensor, Dyadic and Engineering Approaches, Dover Publications, New York, 1967