@article{VMUMM_1987_5_a5,
     author = {A. P. Veselov},
     title = {Time change in integrable systems},
     journal = {Vestnik Moskovskogo universiteta. Matematika, mehanika},
     pages = {25--29},
     year = {1987},
     number = {5},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/VMUMM_1987_5_a5/}
}