TY  - JOUR
AU  - S. P. Tokarev
TI  - The normal form of an analytic system of differential equations in the case of a structurally unstable focus
JO  - Differencialʹnye uravneniâ
PY  - 1977
SP  - 1142
EP  - 1144
VL  - 13
IS  - 6
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/DE_1977_13_6_a24/
LA  - ru
ID  - DE_1977_13_6_a24
ER  -