@article{DAN_1982_267_3_a5,
     author = {V. S. Kryuchkov},
     title = {On the smoothness of the symbol of the {Calderon{\textendash}Zygmund} singular integral operator},
     journal = {Doklady Akademii Nauk},
     pages = {540--544},
     year = {1982},
     volume = {267},
     number = {3},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1982_267_3_a5/}
}