1. Über die Theorie der einfachen Ungleichungen;Farkas;J. Reine & Angew. Math.,1902
2. On Michell trusses;Hegemier;Internat. J. Mech. Sci.,1969
3. Optimum Structures;Hemp,1973
4. Minimum volume design of discs;Hu;J. Appl. Math. & Phys. (ZAMP),1961
5. An analogy between upper bound solutions for plane strain metal working and minimum weight two-dimensional frames;Johnson;Internat. J. Mech. Sci.,1961