@article{GDZPPN002318490,
title = {An Operator Inequality.},
journal = {Mathematische Annalen},
volume = {243},
year = {1979},
pages = {249-250},
zbl = {0407.47012},
url = {http://dml.mathdoc.fr/item/GDZPPN002318490}
}
Hansen, Frank. An Operator Inequality.. Mathematische Annalen, Tome 243 (1979) pp. 249-250. http://gdmltest.u-ga.fr/item/GDZPPN002318490/