@article{DAN_1961_140_5_a1,
     author = {A. S. Blagoveshchenskii},
     title = {Some well-posed problems for the ultrahyperbolic and wave equations with data on the characteristic cone},
     journal = {Doklady Akademii Nauk},
     pages = {990--993},
     publisher = {mathdoc},
     volume = {140},
     number = {5},
     year = {1961},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1961_140_5_a1/}
}