@article{VMUMM_2000_5_a7,
     author = {R. M. Bebenin and Ya. V. Tatarinov},
     title = {Frequency nondegeneracy in problems of celestial mechanics},
     journal = {Vestnik Moskovskogo universiteta. Matematika, mehanika},
     pages = {30--35},
     publisher = {mathdoc},
     number = {5},
     year = {2000},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/VMUMM_2000_5_a7/}
}