16S10 Associative rings determined by universal properties (free algebras, coproducts, adjunction of inverses, etc.) 915

16S34 Group rings [See also 20C05, 20C07], Laurent polynomial rings (associative algebraic aspects) 4624

16S90 Torsion theories; radicals on module categories (associative algebraic aspects) [See also 13D30, 18E40] {For radicals of rings, see 16Nxx} 1503