@article{DAN_1991_321_6_a6,
     author = {Yu. D. Pletner},
     title = {Fundamental solutions of operators of {Sobolev} type},
     journal = {Doklady Akademii Nauk},
     pages = {1155--1157},
     year = {1991},
     volume = {321},
     number = {6},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1991_321_6_a6/}
}