TY  - JOUR
AU  - A. G. Sokolskii
TI  - On the stability of Hamiltonian systems in case of zero frequency
JO  - Differencialʹnye uravneniâ
PY  - 1981
SP  - 1509
EP  - 1510
VL  - 17
IS  - 8
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/DE_1981_17_8_a21/
LA  - ru
ID  - DE_1981_17_8_a21
ER  -