Geodesic
On the problem of distinguishing the center and focus for systems of nonlinear oscillations
Differencialʹnye uravneniâ, Tome 12 (1976) no. 12, pp. 2273-2274 
A. P. Sadovskii. On the problem of distinguishing the center and focus for systems of nonlinear oscillations. Differencialʹnye uravneniâ, Tome 12 (1976) no. 12, pp. 2273-2274. http://geodesic.mathdoc.fr/item/DE_1976_12_12_a19/
@article{DE_1976_12_12_a19,
     author = {A. P. Sadovskii},
     title = {On the problem of distinguishing the center and focus for systems of nonlinear oscillations},
     journal = {Differencialʹnye uravneni\^a},
     pages = {2273--2274},
     year = {1976},
     volume = {12},
     number = {12},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1976_12_12_a19/}
}
TY  - JOUR
AU  - A. P. Sadovskii
TI  - On the problem of distinguishing the center and focus for systems of nonlinear oscillations
JO  - Differencialʹnye uravneniâ
PY  - 1976
SP  - 2273
EP  - 2274
VL  - 12
IS  - 12
UR  - http://geodesic.mathdoc.fr/item/DE_1976_12_12_a19/
LA  - ru
ID  - DE_1976_12_12_a19
ER  - 
%0 Journal Article
%A A. P. Sadovskii
%T On the problem of distinguishing the center and focus for systems of nonlinear oscillations
%J Differencialʹnye uravneniâ
%D 1976
%P 2273-2274
%V 12
%N 12
%U http://geodesic.mathdoc.fr/item/DE_1976_12_12_a19/
%G ru
%F DE_1976_12_12_a19

Voir la notice de l'article provenant de la source Math-Net.Ru