@article{RM_1994_49_1_a18,
     author = {P. I. Topalov},
     title = {The inclusion of the {Klein} bottles in the theory of the topological classification of {Hamiltonian} systems},
     journal = {Trudy Matematicheskogo Instituta imeni V.A. Steklova},
     pages = {248--250},
     publisher = {mathdoc},
     volume = {49},
     number = {1},
     year = {1994},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/RM_1994_49_1_a18/}
}