@article{GDZPPN002418975, title = {Ulm Invariants of the Brauer Group of a Field.}, journal = {Mathematische Zeitschrift}, volume = {154}, year = {1977}, pages = {41-50}, zbl = {0334.20019}, url = {http://dml.mathdoc.fr/item/GDZPPN002418975} }
Schacher, Murray; Fein, Burton. Ulm Invariants of the Brauer Group of a Field.. Mathematische Zeitschrift, Tome 154 (1977) pp. 41-50. http://gdmltest.u-ga.fr/item/GDZPPN002418975/