TY  - JOUR
AU  - I. A. Pasynkova
TI  - The existence of families of periodic solutions of a system of $n$ second order differential equations in the resonance case
JO  - Differencialʹnye uravneniâ
PY  - 1969
SP  - 1984
EP  - 1989
VL  - 5
IS  - 11
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/DE_1969_5_11_a3/
LA  - ru
ID  - DE_1969_5_11_a3
ER  -