“…However, in many cases, this kind of description is insufficient and it is necessary to apply the more general nonlocal elas ticity theory. The need to use this theory arises, for example, in describing the elastic properties of statis tically inhomogeneous media, geological media, com posite and structural materials, crystals with defects, and perturbations in perfect crystals for the case of the characteristic size of perturbation being comparable to the lattice constant [3,[9][10][11][12][13][14][15][16][17][18].…”