참고문헌
- Complete Normed Algebras F.F.Bonsal;J.Dancan
- C*-algberas J.Dixmier
- Internat.J.Math.Math.Sci. v.12-4 Spatial numerical ranges of elements of Banach algebras A.K.Gaur;T.Husain
- Proc.Amer.Math.Soc. v.117-1 Norms on unitizations of Banach algebras A.K.Gaur;Z.V.Kovarik
- to appear in Internat.J.Math.Math.Sci. Spatial numerical ranges of elements of subalgebras of C。(X) S.-E.Takahasi