@article{MZM_1983_34_1_a1,
     author = {V. V. Arestov},
     title = {Approximation of invariant operators},
     journal = {Matemati\v{c}eskie zametki},
     pages = {9--29},
     publisher = {mathdoc},
     volume = {34},
     number = {1},
     year = {1983},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MZM_1983_34_1_a1/}
}