@article{GDZPPN002542234,
title = {Extreme points of numerical ranges of quasihyponormal operators},
journal = {Revista colombiana de matematicas},
volume = {27},
year = {1993},
pages = {223-230},
zbl = {0811.47021},
url = {http://dml.mathdoc.fr/item/GDZPPN002542234}
}
Rodríguez Montes, Jaime. Extreme points of numerical ranges of quasihyponormal operators. Revista colombiana de matematicas, Tome 27 (1993) pp. 223-230. http://gdmltest.u-ga.fr/item/GDZPPN002542234/