@article{DE_1982_18_3_a0,
     author = {V. V. Veremenyuk},
     title = {Criterion for upper semicontinuity of the $i$th {Lyapunov} exponent of a linear {Hamiltonian} system of differential equations},
     journal = {Differencialʹnye uravneni\^a},
     pages = {371--383},
     publisher = {mathdoc},
     volume = {18},
     number = {3},
     year = {1982},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1982_18_3_a0/}
}