@article{RM_1970_25_5_a16,
     author = {A. B. Katok},
     title = {Winding numbers and~$C$-flows},
     journal = {Trudy Matematicheskogo Instituta imeni V.A. Steklova},
     publisher = {mathdoc},
     volume = {25},
     number = {5},
     year = {1970},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/RM_1970_25_5_a16/}
}