1. Direct limit analysis via rigid-plastic finite elements;Nguyen Dang Hung;Comp. Meths. Appl. Mech. Eng.,1976
2. Plastic analysis of structures;Hodge,1959
3. Plastic analysis and design;Massonnet,1965
4. General theorems of elastic-plastic solids;Koiter,1960
5. Methods of linear programming in analysis of elastic-plastic systems;Chyras,1969