TY  - JOUR
AU  - A. P. Sadovskii
TI  - A problem of distinguishing the center and focus for a case of a complex singular point
JO  - Differencialʹnye uravneniâ
PY  - 1986
SP  - 789
EP  - 794
VL  - 22
IS  - 5
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/DE_1986_22_5_a7/
LA  - ru
ID  - DE_1986_22_5_a7
ER  -