TY - JOUR AU - V. I. Burenkov TI - The approximation of functions in the space $C^{r}(\Omega )$ by functions of compact support, for an arbitrary open set~$\Omega $ JO - Trudy Matematicheskogo Instituta imeni V.A. Steklova PY - 1972 SP - 62 EP - 74 VL - 117 PB - mathdoc UR - http://geodesic.mathdoc.fr/item/TM_1972_117_a4/ LA - ru ID - TM_1972_117_a4 ER -