@article{DAN_1962_147_4_a7,
     author = {N. S. Landkof},
     title = {On a general theory of linear filters},
     journal = {Doklady Akademii Nauk},
     pages = {776--778},
     year = {1962},
     volume = {147},
     number = {4},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1962_147_4_a7/}
}