Voir la notice de l'article provenant de la source Math-Net.Ru
@article{DAN_1960_132_5_a4, author = {S. A. Gal'pern}, title = {Lacunae of non-hyperbolic equations}, journal = {Doklady Akademii Nauk}, pages = {990--993}, publisher = {mathdoc}, volume = {132}, number = {5}, year = {1960}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/DAN_1960_132_5_a4/} }
S. A. Gal'pern. Lacunae of non-hyperbolic equations. Doklady Akademii Nauk, Tome 132 (1960) no. 5, pp. 990-993. http://geodesic.mathdoc.fr/item/DAN_1960_132_5_a4/