TY  - JOUR
AU  - V. V. Velichenko
TI  - On sufficient conditions for optimality for multisheeted fields of extremals
JO  - Doklady Akademii Nauk
PY  - 1976
SP  - 757
EP  - 760
VL  - 226
IS  - 4
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/DAN_1976_226_4_a3/
LA  - ru
ID  - DAN_1976_226_4_a3
ER  -