@article{FAA_1969_3_4_a7,
     author = {V. I. Arnol'd},
     title = {One-dimensional cohomologies of {Lie} algebras of nondivergent vector fields and rotation numbers of dynamic systems},
     journal = {Funkcionalʹnyj analiz i ego prilo\v{z}eni\^a},
     pages = {77--78},
     publisher = {mathdoc},
     volume = {3},
     number = {4},
     year = {1969},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/FAA_1969_3_4_a7/}
}