@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/