@article{SM_1972_16_2_a1,
     author = {V. N. Gol'dberg},
     title = {Discontinuous solutions of nonlinear mixed problems for hyperbolic equations on a~plane},
     journal = {Sbornik. Mathematics},
     pages = {159--180},
     publisher = {mathdoc},
     volume = {16},
     number = {2},
     year = {1972},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_1972_16_2_a1/}
}