@article{IM2_1975_9_4_a3,
     author = {G. G. Kasparov},
     title = {Topological invariants of elliptic {operators.~I.} $K$-homology},
     journal = {Izvestiya. Mathematics },
     pages = {751--792},
     publisher = {mathdoc},
     volume = {9},
     number = {4},
     year = {1975},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/IM2_1975_9_4_a3/}
}