@article{TM_1994_205_a3,
     author = {A. V. Bolsinov and A. T. Fomenko},
     title = {Unsolved problems in the theory of topological classification of integrable systems},
     journal = {Trudy Matematicheskogo Instituta imeni V.A. Steklova},
     pages = {18--31},
     publisher = {mathdoc},
     volume = {205},
     year = {1994},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/TM_1994_205_a3/}
}