@article{DAN_1984_275_3_a5,
     author = {G. G. Kasparov},
     title = {Lorentz groups: $K$-theory of unitary representations and crossed},
     journal = {Doklady Akademii Nauk},
     pages = {541--545},
     publisher = {mathdoc},
     volume = {275},
     number = {3},
     year = {1984},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1984_275_3_a5/}
}