@article{IM2_1983_21_2_a4,
     author = {V. N. Kolokoltsov},
     title = {Geodesic flows on two-dimensional manifolds with an additional first integral that is polynomial in the velocities},
     journal = {Izvestiya. Mathematics},
     pages = {291--306},
     year = {1983},
     volume = {21},
     number = {2},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/IM2_1983_21_2_a4/}
}