@article{DAN_1963_152_1_a6,
     author = {A. V. Efimov},
     title = {On nonsummability of orthogonal series by linear methods},
     journal = {Doklady Akademii Nauk},
     pages = {31--34},
     publisher = {mathdoc},
     volume = {152},
     number = {1},
     year = {1963},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1963_152_1_a6/}
}