@article{MZM_1970_7_6_a8,
     author = {A. I. Kamzolov},
     title = {Order of approximation of functions of the class $Z_2(E^n)$ by linear positive convolution operators},
     journal = {Matemati\v{c}eskie zametki},
     pages = {723--732},
     year = {1970},
     volume = {7},
     number = {6},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MZM_1970_7_6_a8/}
}