TY - JOUR AU - G. S. Smirnov TI - On a~criterion for an element of best $(\alpha,\beta)$-approximation in the space of summable functions JO - Trudy Matematicheskogo Instituta imeni V.A. Steklova PY - 1987 SP - 201 EP - 202 VL - 180 PB - mathdoc UR - http://geodesic.mathdoc.fr/item/TM_1987_180_a122/ LA - ru ID - TM_1987_180_a122 ER -