TY  - JOUR
AU  - Tung Chin-chu
TI  - Positions of limit-cycles of the system $\frac{dx}{dt}=\sum_{0\le{i+k}\le2}a_{ik}x^iy^k$, $\frac{dy}{dt}=\sum_{0\le{i+k}\le2}b_{ik}x^iy^k$
JO  - Matematika
PY  - 1962
SP  - 150
EP  - 168
VL  - 6
IS  - 2
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/MAT_1962_6_2_a4/
LA  - ru
ID  - MAT_1962_6_2_a4
ER  -