@article{DAN_1985_285_3_a8,
     author = {N. Yu. Kapustin},
     title = {Three boundary value problems for a hyperbolic equation in a},
     journal = {Doklady Akademii Nauk},
     pages = {555--558},
     publisher = {mathdoc},
     volume = {285},
     number = {3},
     year = {1985},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1985_285_3_a8/}
}