@article{RM_1974_29_5_a13,
     author = {G. A. Kats},
     title = {Euler cohomology classes, and homotopic approximation},
     journal = {Trudy Matematicheskogo Instituta imeni V.A. Steklova},
     publisher = {mathdoc},
     volume = {29},
     number = {5},
     year = {1974},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/RM_1974_29_5_a13/}
}