@article{DE_1968_4_7_a17,
     author = {N. J. Yurchuk},
     title = {The {Goursat} problem for a second order hyperbolic equation of a special form},
     journal = {Differencialʹnye uravneni\^a},
     pages = {1333--1345},
     publisher = {mathdoc},
     volume = {4},
     number = {7},
     year = {1968},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1968_4_7_a17/}
}