@article{DE_1972_8_4_a17,
     author = {M. E. Drakhlin},
     title = {Some topological properties of a certain integral operator},
     journal = {Differencialʹnye uravneni\^a},
     pages = {721--724},
     publisher = {mathdoc},
     volume = {8},
     number = {4},
     year = {1972},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1972_8_4_a17/}
}