@article{DAN_1971_196_2_a12,
     author = {S. G. Samko},
     title = {Operators of potential type},
     journal = {Doklady Akademii Nauk},
     pages = {299--301},
     publisher = {mathdoc},
     volume = {196},
     number = {2},
     year = {1971},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1971_196_2_a12/}
}