@article{DAN_1960_135_5_a5,
     author = {A. A. Dezin},
     title = {Invariant hyperbolic systems and the {Goursat} problem},
     journal = {Doklady Akademii Nauk},
     pages = {1042--1045},
     publisher = {mathdoc},
     volume = {135},
     number = {5},
     year = {1960},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1960_135_5_a5/}
}