@article{DE_1977_13_12_a13,
     author = {F. T. Baranovskii},
     title = {The {Goursat} problem for a second order hyperbolic equation with a singularity in the coefficient},
     journal = {Differencialʹnye uravneni\^a},
     pages = {2234--2245},
     publisher = {mathdoc},
     volume = {13},
     number = {12},
     year = {1977},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1977_13_12_a13/}
}