@article{01505958,
title = {Spatial numerical ranges of elements of subalgebras of },
journal = {International Journal of Mathematics and Mathematical Sciences},
volume = {23},
year = {2000},
pages = {827-831},
doi = {10.1155/S0161171200003148},
zbl = {0970.46036},
language = {en},
url = {http://dml.mathdoc.fr/item/01505958}
}
Takahasi, Sin-Ei. Spatial numerical ranges of elements of subalgebras of . International Journal of Mathematics and Mathematical Sciences, Tome 23 (2000) pp. 827-831. doi : 10.1155/S0161171200003148. http://gdmltest.u-ga.fr/item/01505958/