@article{1178243352,
author = {Sait\^o, Teishir\^o},
title = {Numerical ranges of tensor products of operators},
journal = {Tohoku Math. J. (2)},
volume = {19},
number = {4},
year = {1967},
pages = { 98-100},
language = {en},
url = {http://dml.mathdoc.fr/item/1178243352}
}
Saitô, Teishirô. Numerical ranges of tensor products of operators. Tohoku Math. J. (2), Tome 19 (1967) no. 4, pp. 98-100. http://gdmltest.u-ga.fr/item/1178243352/