@article{IM2_2019_83_6_a1,
     author = {V. V. Vedyushkina (Fokicheva) and A. T. Fomenko},
     title = {Integrable geodesic flows on orientable two-dimensional surfaces and topological billiards},
     journal = {Izvestiya. Mathematics },
     pages = {1137--1173},
     publisher = {mathdoc},
     volume = {83},
     number = {6},
     year = {2019},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/IM2_2019_83_6_a1/}
}