@article{IM2_1971_5_1_a13,
     author = {N. I. Gurarii},
     title = {Coefficient sequences in {Hilbert} and {Banach} space expansions},
     journal = {Izvestiya. Mathematics},
     pages = {226--232},
     year = {1971},
     volume = {5},
     number = {1},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/IM2_1971_5_1_a13/}
}