@article{DE_1976_12_1_a23,
     author = {P. T. Dybov},
     title = {On the question of the composition of singular integrals},
     journal = {Differencialʹnye uravneni\^a},
     pages = {180--182},
     publisher = {mathdoc},
     volume = {12},
     number = {1},
     year = {1976},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1976_12_1_a23/}
}