The principle of limit absorption and A. G. Sveshnikov's partial conditions of radition for Helmholts equation in multile dimensinal layer with impedance boundary conditions were studied. The behavior of the solutions of corresponding initial-boundary value problem for non-stationary wave equations as t \ra+\infty was studied too.
ISKENDEROV, B. A. and MEHTIEVA, A. I. (1996) "PIRINCIPLES OF RADIATION FOR HELMHOLTZ EQUATION IN N-DIMENSIONAL LAYER WITH IMPEDENCE BOUNDARY CONDITIONS.," Turkish Journal of Mathematics: Vol. 20: No. 3, Article 1. Available at: https://journals.tubitak.gov.tr/math/vol20/iss3/1