TY - JOUR AU - A. M. Il'in TI - A boundary value problem for the elliptic equation of second order in a domain with a narrow slit. 1. The two-dimensional case JO - Sbornik. Mathematics PY - 1976 SP - 459 EP - 480 VL - 28 IS - 4 UR - http://geodesic.mathdoc.fr/item/SM_1976_28_4_a1/ LA - en ID - SM_1976_28_4_a1 ER -