@article{TRSPY_1961_62_a0,
     author = {A. V. Efimov},
     title = {Linear methods of approximating certain classes of continuous periodic functions},
     journal = {Informatics and Automation},
     pages = {3--47},
     publisher = {mathdoc},
     volume = {62},
     year = {1961},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/TRSPY_1961_62_a0/}
}