@article{GDZPPN002318245, title = {Pfister Ideals in Witt Rings.}, journal = {Mathematische Annalen}, volume = {243}, year = {1979}, pages = {219-246}, zbl = {0401.10032}, url = {http://dml.mathdoc.fr/item/GDZPPN002318245} }
Lam, T.Y.; Elman, R.; Wadsworth, A.R. Pfister Ideals in Witt Rings.. Mathematische Annalen, Tome 243 (1979) pp. 219-246. http://gdmltest.u-ga.fr/item/GDZPPN002318245/