@article{DAN_1971_197_2_a0,
     author = {Sh. A. Akhmedov},
     title = {On the extension of generalized solutions of differential equations defined in the neighborhood of characteristic subspaces},
     journal = {Doklady Akademii Nauk},
     pages = {255--256},
     publisher = {mathdoc},
     volume = {197},
     number = {2},
     year = {1971},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1971_197_2_a0/}
}