TY  - JOUR
AU  - L. V. Detchenya
AU  - A. P. Sadovskii
TI  - Letter to the editors: ``Orbital normal forms of two-dimensional analytic systems with zero linear and nonzero quadratic parts'' [Differ. Uravn. \textbf{35} (1999), no. 1, 51--57, 141; MR1723202]
JO  - Differencialʹnye uravneniâ
PY  - 2000
SP  - 1580
VL  - 36
IS  - 11
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/DE_2000_36_11_a21/
LA  - ru
ID  - DE_2000_36_11_a21
ER  -