1. M. J. Turner, R. W. Clough, H. C. Martin and L. J. Topp, J. Aerospace Sci. 23 (1956) p. 805.
2. R. W. Clough, The Finite Element Method in Plane Stress Analysis. Second Conference on Electronic Computation, Pittsburgh, Pa., Proc. ASCE, 1960, p. 345.
3. Tech. Report;E. L. Wilson,1963
4. R. H. Gallagher, J. Padlog and P. P. Bijlaard, J. Am. Rocket Soc. 32 (1962) p. 700.
5. J. H. Argyris, J. Roy. Aero. Soc. 69 (1965) p. 633.