1. A definition of stable inelastic material;Drucker, D. C.;J. Appl. Mech.,1959
2. A more fundamental approach to plastic stress-strain relations;Drucker, D. C.,1952
3. On uniqueness in linear viscoelasticity;Breuer, S.;Quart. Appl. Math.,1962
4. Viscoelastic stress analysis;Lee, E. H.,1960