@article{DE_1968_4_2_a7,
     author = {V. V. Ostroumov},
     title = {The unique solvability of de la {Vall\'ee} {Poussin's} problem},
     journal = {Differencialʹnye uravneni\^a},
     pages = {261--268},
     publisher = {mathdoc},
     volume = {4},
     number = {2},
     year = {1968},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1968_4_2_a7/}
}