TY - JOUR AU - V. I. Burenkov TI - The density of infinitely differentiable functions in Sobolev spaces for an arbitrary open set JO - Trudy Matematicheskogo Instituta imeni V.A. Steklova PY - 1974 SP - 39 EP - 50 VL - 131 PB - mathdoc UR - http://geodesic.mathdoc.fr/item/TM_1974_131_a4/ LA - ru ID - TM_1974_131_a4 ER -