TY  - JOUR
AU  - N. A. Izobov
TI  - The transfer of the Lyapunov integral criterion to two-dimensional periodic systems of second order
JO  - Matematičeskie zametki
PY  - 1977
SP  - 817
EP  - 828
VL  - 21
IS  - 6
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/MZM_1977_21_6_a8/
LA  - ru
ID  - MZM_1977_21_6_a8
ER  -