1. Schofield AN, Wroth CP, Critical state soil mechanics. Mc Graw–Hill, London, 1968
2. Dafalias YF, Herrmann LR (1980) A bounding surface soil plasticity model. Proc. Int. Symp. Soils under Cycl. Trans. Loading, Swansea, pp 335–345
3. Krieg RD (1975) A practical two surface plasticity theory. J Appl Mech 42:641–646
4. Hashiguchi K (1980) Constitutive equations of elastoplastic materials with elastic-plastic transition. J Appl Mech 47:266–272
5. Hashiguchi K (1986) A mathematical description of elasto-plastic deformation in normal-yield and sub-yield states, Proc. 2nd Int. Symposium on Numerical Models in Geomechanics “NUMOG 2″, Ghent, pp 17–24