@article{TAM_2019_46_1_a4,
     author = {A. T. Fomenko and V. V. Vedyushkina},
     title = {Singularities of integrable {Liouville} systems, reduction of integrals to lower degree and topological billiards: recent results},
     journal = {Theoretical and applied mechanics},
     pages = {47 - 63},
     publisher = {mathdoc},
     volume = {46},
     number = {1},
     year = {2019},
     url = {http://geodesic.mathdoc.fr/item/TAM_2019_46_1_a4/}
}