@article{1077467478,
author = {Marcus, Marvin},
title = {Convex functions of quadratic forms},
journal = {Duke Math. J.},
volume = {24},
number = {1},
year = {1957},
pages = { 321-326},
language = {en},
url = {http://dml.mathdoc.fr/item/1077467478}
}
Marcus, Marvin. Convex functions of quadratic forms. Duke Math. J., Tome 24 (1957) no. 1, pp. 321-326. http://gdmltest.u-ga.fr/item/1077467478/