T. Liszka, An Interpolation method for an irregular net of nodes, Int. J. Num. Meth. Eng, vol.20, pp.1599-1612, 1984.

T. Liszka and J. Orkisz, The ®nite difference method at arbitrary irregular grids and its application in applied mechanics, Comp. Struct, vol.11, pp.83-95, 1980.

T. Liszka and J. Orkisz, Solution of nonlinear problems of mechanics by the ®nite difference method at arbitrary meshes, Comp. Mech, vol.5, pp.117-130, 1983.

T. J. Liszka, C. Duarte, and W. W. Tworzydlo, hp-Meshless cloud method, Comput. Meth. Appl. Mech. Eng, p.139, 1996.

B. Nayroles, G. Touzot, and P. Villon, Generalizing the ®nite element method: diffuse approximation and diffuse elements, Comput. Mech, vol.10, pp.307-318, 1992.

J. Orkisz, Meshless ®nite difference method. I. Basic approach, II. Adaptive approach, IACM-Fourth World Congress on computational mechanics, Comp. Struct, vol.14, issue.5±6, pp.509-511, 1981.

S. P. Timoshenko and J. N. Goodier, Theory of elasticity, 1987.