@article{SM_2018_209_11_a4,
     author = {D. S. Timonina},
     title = {Liouville classification of integrable geodesic flows in a~potential field on two-dimensional manifolds of revolution: the torus and the {Klein} bottle},
     journal = {Sbornik. Mathematics},
     pages = {1644--1676},
     publisher = {mathdoc},
     volume = {209},
     number = {11},
     year = {2018},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_2018_209_11_a4/}
}