TY  - JOUR
AU  - V. L. Levin
TI  - Application of E.~Helly's theorem to convex programming, problems of best approximation and related questions
JO  - Sbornik. Mathematics
PY  - 1969
SP  - 235
EP  - 247
VL  - 8
IS  - 2
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/SM_1969_8_2_a5/
LA  - en
ID  - SM_1969_8_2_a5
ER  -