@article{DE_1988_24_4_a32,
     author = {T. V. Chekmarev},
     title = {A nonlocal problem for a system of equations of {Helmholtz} type},
     journal = {Differencialʹnye uravneni\^a},
     pages = {724--726},
     year = {1988},
     volume = {24},
     number = {4},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1988_24_4_a32/}
}