@article{GDZPPN002412608, title = {Quadratic Forms and the u-Invariant. I.}, journal = {Mathematische Zeitschrift}, volume = {135}, year = {1973}, pages = {283-304}, zbl = {0244.10020}, url = {http://dml.mathdoc.fr/item/GDZPPN002412608} }
Elman, Richard; Lam, Tsit-Yuen. Quadratic Forms and the u-Invariant. I.. Mathematische Zeitschrift, Tome 135 (1973) pp. 283-304. http://gdmltest.u-ga.fr/item/GDZPPN002412608/