%0 Journal Article
%A AKEMANN, CHARLES A.
%A ANDERSON, JOEL
%T THE SPECTRAL SCALE AND THE $k$–NUMERICAL RANGE
%J Glasgow mathematical journal
%D 2003
%P 225-238
%V 45
%N 2
%U http://geodesic.mathdoc.fr/articles/10.1017/S0017089503001320/
%R 10.1017/S0017089503001320
%F 10_1017_S0017089503001320