@article{DAN_1978_243_4_a6,
     author = {V. A. Korobitsyn and O. B. Sidonskii},
     title = {A difference operator on a group over a matrix ring},
     journal = {Doklady Akademii Nauk},
     pages = {847--850},
     publisher = {mathdoc},
     volume = {243},
     number = {4},
     year = {1978},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1978_243_4_a6/}
}