TY  - JOUR
AU  - V. I. Chemodanov
TI  - Isochronism in the case of a focus
JO  - Differencialʹnye uravneniâ
PY  - 1969
SP  - 964
EP  - 966
VL  - 5
IS  - 5
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/DE_1969_5_5_a20/
LA  - ru
ID  - DE_1969_5_5_a20
ER  -