@article{DAN_1960_132_1_a0,
     author = {Yu. M. Berezanskii},
     title = {Energy inequalities for some classes of equations of mixed type},
     journal = {Doklady Akademii Nauk},
     pages = {9--12},
     publisher = {mathdoc},
     volume = {132},
     number = {1},
     year = {1960},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1960_132_1_a0/}
}