@article{TM_1987_180_a32,
     author = {V. I. Burenkov},
     title = {Approximation by infinitely differentiable functions with preservation of boundary values},
     journal = {Trudy Matematicheskogo Instituta imeni V.A. Steklova},
     pages = {68--70},
     publisher = {mathdoc},
     volume = {180},
     year = {1987},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/TM_1987_180_a32/}
}