@article{DAN_1971_196_1_a15,
     author = {S. V. Uspenskii},
     title = {Differential properties for solutions of a class of partial differential equations in unbounded regions},
     journal = {Doklady Akademii Nauk},
     pages = {61--64},
     publisher = {mathdoc},
     volume = {196},
     number = {1},
     year = {1971},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1971_196_1_a15/}
}