Abstract
Popescu, D
Popescu, D (通讯作者),Romanian Acad, Simian Stoilow Inst Math, Res Unit 5, POB 1-764, Bucharest 014700, Romania.;Popescu, D (通讯作者),Univ Bucharest, Fac Math & Comp Sci, Str Acad 14, RO-010014 Bucharest 1, Romania.
BULLETIN MATHEMATIQUE DE LA SOCIETE DES SCIENCES MATHEMATIQUES DE ROUMANIE, 2022; 65 (2): 253