TY - JOUR AU - P. A. Borodin TI - Quasiorthogonal sets and conditions for a~Banach space to be a~Hilbert space JO - Sbornik. Mathematics PY - 1997 SP - 1171 EP - 1182 VL - 188 IS - 8 PB - mathdoc UR - http://geodesic.mathdoc.fr/item/SM_1997_188_8_a3/ LA - en ID - SM_1997_188_8_a3 ER -