@article{IM2_2001_65_3_a9,
     author = {V. A. Skvortsov},
     title = {$A$-integrable martingale sequences and {Walsh} series},
     journal = {Izvestiya. Mathematics },
     pages = {607--615},
     publisher = {mathdoc},
     volume = {65},
     number = {3},
     year = {2001},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/IM2_2001_65_3_a9/}
}