@article{DE_1985_21_3_a0,
     author = {V. A. Il'in},
     title = {A necessary condition for equiconvergence of the trigonometric series and of a spectral expansion for an arbitrary integrable function},
     journal = {Differencialʹnye uravneni\^a},
     pages = {371--379},
     publisher = {mathdoc},
     volume = {21},
     number = {3},
     year = {1985},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1985_21_3_a0/}
}