@article{DAN_1957_113_6_a2,
     author = {Yu. A. Kaz'min},
     title = {On complete systems and bases in $L_2$},
     journal = {Doklady Akademii Nauk},
     pages = {1199--1202},
     publisher = {mathdoc},
     volume = {113},
     number = {6},
     year = {1957},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1957_113_6_a2/}
}