Bonsall, F. F., & Duncan, J. Numerical ranges of operators on normal spaces and of elements of Normed Algebras.
Chicago Edition CitationBonsall, F F., and J. Duncan. Numerical Ranges of Operators on Normal Spaces and of Elements of Normed Algebras. New York, Cambridge at the University Press.
MLA Edition CitationBonsall, F F., and J. Duncan. Numerical Ranges of Operators on Normal Spaces and of Elements of Normed Algebras.
Warning: These citations may not always be 100% accurate.