@article{MZM_1971_9_6_a13,
     author = {O. A. Gavrilova},
     title = {The infinitely differentiable extension of systems of functions},
     journal = {Matemati\v{c}eskie zametki},
     pages = {723--734},
     publisher = {mathdoc},
     volume = {9},
     number = {6},
     year = {1971},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MZM_1971_9_6_a13/}
}