Sommerfeld-type conditions and uniqueness of the solution of exterior problems of the theory of elastic vibrations of aneotropic media : PMM vol. 43, no. 6, 1979, pp. 1102–1110

Steady vibrations of unbounded elastic anisotropic media are considered in three dimensions in the general case of 21 elastic constants. The problem is posed of extracting a single solution, defined in the whole space, of a system of elliptic equations for the stationary part of the displacement. The asymptotic of the fundamental solution is investigated at infinity and radiation conditions are determined which go directly over into the Sommerfeld conditions when going over to isotropic media. A uniqueness theorem is formulated for the inhomogeneous problem in unbounded domains.