@article{DAN_1960_135_4_a0,
     author = {T. G. Gegelia},
     title = {Composition of singular kernels},
     journal = {Doklady Akademii Nauk},
     pages = {767--770},
     publisher = {mathdoc},
     volume = {135},
     number = {4},
     year = {1960},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1960_135_4_a0/}
}