@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/