@article{DAN_1969_186_6_a4,
     author = {I. A. Kipriyanov and M. I. Klyuchantsev},
     title = {The boundedness of a certain class of singular integral operators},
     journal = {Doklady Akademii Nauk},
     pages = {1253--1255},
     publisher = {mathdoc},
     volume = {186},
     number = {6},
     year = {1969},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1969_186_6_a4/}
}