@article{GMJ_1994__1_3_47128,
     author = {Bareladze, G.},
     title = {On convergence subsystems of orthonormal systems.},
     journal = {Georgian Mathematical Journal},
     pages = {235--242},
     publisher = {mathdoc},
     volume = {1},
     number = {3},
     year = {1994},
     zbl = {0811.42009},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/GMJ_1994__1_3_47128/}
}