TY  - JOUR
AU  - A. A. Tolstonogov
TI  - A~theorem of existence of an optimal control for the Goursat--Darboux problem without convexity assumptions
JO  - Izvestiya. Mathematics 
PY  - 2000
SP  - 807
EP  - 826
VL  - 64
IS  - 4
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/IM2_2000_64_4_a5/
LA  - en
ID  - IM2_2000_64_4_a5
ER  -