@article{DE_1984_20_10_a10,
     author = {O. Vejvoda and M. Shtedry},
     title = {Existence of classical periodic solutions of the wave equation. {The} relation of the number-theoretic character of the period and the geometric properties of solutions},
     journal = {Differencialʹnye uravneni\^a},
     pages = {1733--1739},
     publisher = {mathdoc},
     volume = {20},
     number = {10},
     year = {1984},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1984_20_10_a10/}
}