TY  - JOUR
AU  - N. A. Zboychik
TI  - Quadratic integrals of linear systems of differential equations
JO  - Differencialʹnye uravneniâ
PY  - 1970
SP  - 381
EP  - 384
VL  - 6
IS  - 2
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/DE_1970_6_2_a19/
LA  - ru
ID  - DE_1970_6_2_a19
ER  -