@article {61918,
	title = {On the numerical range and norm of elementary operators},
	journal = {Linear and multilinear algebraLinear and Multilinear Algebra},
	volume = {52},
	year = {2004},
	month = {2004},
	pages = {293-302},
	isbn = {0308-1087},
	author = {Seddik, Ameur}
}
