@article{1103036144, author = {Stampfli, Joseph G.}, title = {Hyponormal operators.}, journal = {Pacific J. Math.}, volume = {12}, number = {4}, year = {1962}, pages = { 1453-1458}, language = {en}, url = {http://dml.mathdoc.fr/item/1103036144} }
Stampfli, Joseph G. Hyponormal operators.. Pacific J. Math., Tome 12 (1962) no. 4, pp. 1453-1458. http://gdmltest.u-ga.fr/item/1103036144/