@article{DAN_1972_202_3_a4,
     author = {V. N. Gol'dberg},
     title = {Branching of solutions of nonlinear mixed problems for almost linear hyperbolic systems on the plane},
     journal = {Doklady Akademii Nauk},
     pages = {518--521},
     publisher = {mathdoc},
     volume = {202},
     number = {3},
     year = {1972},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1972_202_3_a4/}
}