TY  - JOUR
AU  - V. P. Fedotov
TI  - The extremum principle for a system of equations
JO  - Differencialʹnye uravneniâ
PY  - 1980
SP  - 679
EP  - 683
VL  - 16
IS  - 4
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/DE_1980_16_4_a9/
LA  - ru
ID  - DE_1980_16_4_a9
ER  -