@article{SM_1997_188_7_a4,
     author = {N. V. Denisova},
     title = {The structure of infinitesimal symmetries of geodesic flows on a~two-dimensional torus},
     journal = {Sbornik. Mathematics},
     pages = {1055--1069},
     publisher = {mathdoc},
     volume = {188},
     number = {7},
     year = {1997},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_1997_188_7_a4/}
}