1. The limit of economy of material in frame structures;Michell;Phil. Mag. Series VI,1904
2. Optimum design methods for multiple loading;Shield;J. appl. Mech. (ZAMP).,1963
3. Design of optimum structures;Venkayya,1970
4. The use of optimality criteria in automated structural design;Gellatly,1971
5. Nonlinear Programming: Sequential Unconstrained Minimization Techniques;Fiacco,1968