1. Energy theorems and structural analysis;Argyris,1960
2. P.H. Denke, A general digital computer analysis of statically indeterminate structures, in: NASA-TD-D-1666, 1962.
3. A.M. Levien, M. Hartz, Dynamic flexibility matrix analysis of frames, in: ASCE, ST4, Vol. 89, 1963, pp. 515–535.
4. Upper and lower bounds in matrix structural analysis;Veubeke,1964
5. Displacement and Equilibrium Models in the Finite Element Method, Stress Analysis;Fraeijs de Veubeke,1965