@article{EJDE_1999__1999__a90,
     author = {Pulkina,  L.S.},
     title = {A non-local problem with integral conditions for hyperbolic equations},
     journal = {Electronic journal of differential equations},
     year = {1999},
     volume = {1999},
     zbl = {0935.35027},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/EJDE_1999__1999__a90/}
}