TY - JOUR TI - Shorts of operators and some extremal problems T3 - Acta scientiarum mathematicarum AU - Pekarev È. L. PY - 1992 LA - English SN - 0001-6969 UR - http://acta.bibl.u-szeged.hu/15339/1/math_056_fasc_001_002_147-163.pdf ER -