@article{05668359,
title = {Davis' convexity theorem and extremal ellipsoids.},
journal = {Beitr\"age zur Algebra und Geometrie},
volume = {51},
year = {2010},
pages = {263-274},
zbl = {1202.52003},
language = {en},
url = {http://dml.mathdoc.fr/item/05668359}
}
Weber, Matthias J.; Schröcker, Hans-Peter. Davis' convexity theorem and extremal ellipsoids.. Beiträge zur Algebra und Geometrie, Tome 51 (2010) pp. 263-274. http://gdmltest.u-ga.fr/item/05668359/