TY  - JOUR
AU  - G. N. Petrovskiǐ
TI  - Certain properties of generalized $\phi$-invariant systems of linear differential equations
JO  - Differencialʹnye uravneniâ
PY  - 1974
SP  - 258
EP  - 264
VL  - 10
IS  - 2
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/DE_1974_10_2_a9/
LA  - ru
ID  - DE_1974_10_2_a9
ER  -