@article{VMUMM_2000_3_a14,
     author = {I. N. Sergeev},
     title = {On the attainability of minimal exponents in the class of infinitesimal perturbations},
     journal = {Vestnik Moskovskogo universiteta. Matematika, mehanika},
     pages = {61--63},
     year = {2000},
     number = {3},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/VMUMM_2000_3_a14/}
}