@article{MZ_1991__206_1_174252,
     author = {J. A\"o\"oell and V.I. Nazarov and P.P. Zabrejko},
     title = {Composing infinitely differentiable functions.},
     journal = {Mathematische Zeitschrift},
     pages = {659--670},
     publisher = {mathdoc},
     volume = {206},
     number = {1},
     year = {1991},
     zbl = {0712.47054},
     url = {http://geodesic.mathdoc.fr/item/MZ_1991__206_1_174252/}
}