@article{GDZPPN002432625, title = {Sums of Squares of Linear Forms.}, journal = {Mathematische Zeitschrift}, volume = {192}, year = {1986}, pages = {297-306}, zbl = {0598.10032}, url = {http://dml.mathdoc.fr/item/GDZPPN002432625} }
Baeza, R.; Leep, D.; O'Ryan, M. Sums of Squares of Linear Forms.. Mathematische Zeitschrift, Tome 192 (1986) pp. 297-306. http://gdmltest.u-ga.fr/item/GDZPPN002432625/