TY - JOUR AU - S. L. Edelstein TI - Asymptotic splitting of boundary-value problems for the Helmholtz equation in a~strip with ``permeable'' boundaries JO - Izvestiya. Mathematics PY - 1997 SP - 877 EP - 898 VL - 61 IS - 4 PB - mathdoc UR - http://geodesic.mathdoc.fr/item/IM2_1997_61_4_a9/ LA - en ID - IM2_1997_61_4_a9 ER -