@article{2311, author = {Putnam, C.R.}, title = {Commutators and normal operators}, journal = {Portugaliae mathematica}, volume = {17}, year = {1958}, pages = {59-62}, zbl = {0151.20102}, mrnumber = {0098989}, language = {en}, url = {http://dml.mathdoc.fr/item/2311} }
Putnam, C.R. Commutators and normal operators. Portugaliae mathematica, Tome 17 (1958) pp. 59-62. http://gdmltest.u-ga.fr/item/2311/