@article{DAN_1980_252_5_a4,
     author = {I. A. Kipriyanov and L. A. Ivanov},
     title = {Hadamard's method for some classes of hyperbolic equations},
     journal = {Doklady Akademii Nauk},
     pages = {1045--1048},
     publisher = {mathdoc},
     volume = {252},
     number = {5},
     year = {1980},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1980_252_5_a4/}
}