Saunders, B. David; Schneider, Hans A symmetric numerical range for matrices. (English) Zbl 0312.65034 Numer. Math. 26, 99-105 (1976). MSC: 65F35 15A12 PDFBibTeX XMLCite \textit{B. D. Saunders} and \textit{H. Schneider}, Numer. Math. 26, 99--105 (1976; Zbl 0312.65034) Full Text: DOI EuDML
Schneider, Hans; Turner, Robert E. L. Matrices Hermitian for an absolute norm. (English) Zbl 0278.15012 Linear Multilinear Algebra 1, 9-31 (1973). MSC: 15B57 15A60 PDFBibTeX XML Full Text: DOI Link