@article{DAN_1961_141_3_a7,
     author = {V. A. Il'in and I. A. Shishmarev},
     title = {Smoothness properties of generalized potentials of an elliptic operator},
     journal = {Doklady Akademii Nauk},
     pages = {547--550},
     publisher = {mathdoc},
     volume = {141},
     number = {3},
     year = {1961},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1961_141_3_a7/}
}