Columbia subject headings:
Associative rings.
C*-algebras.
Grothendieck groups.
Representations of groups.
Von Neumann regular rings.
Harvard subject headings:
Associative rings.
C*-algebras.
Grothendieck groups.
Representations of groups.
Von Neumann regular rings.
Princeton subject headings:
Associative rings (Algebra)
C*-algebras.
Grothendieck groups.
Representations of groups.
Von Neumann regular rings.