TY  - JOUR
AU  - A. P. Vorob'ev
TI  - Qualitative investigation in the large of integral curves of isochronous systems of two differential equations
JO  - Differencialʹnye uravneniâ
PY  - 1965
SP  - 439
EP  - 441
VL  - 1
IS  - 4
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/DE_1965_1_4_a1/
LA  - ru
ID  - DE_1965_1_4_a1
ER  -