@article{DE_1969_5_5_a11,
     author = {N. J. Yurchuk},
     title = {A partially characteristic mixed problem with {Goursat} initial conditions for linear equations with two-dimensional time},
     journal = {Differencialʹnye uravneni\^a},
     pages = {898--910},
     publisher = {mathdoc},
     volume = {5},
     number = {5},
     year = {1969},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1969_5_5_a11/}
}