Sums of Squares in Division Algebras. A. Wadsworth; D.B. Leep; D.B. Shapiro — 1985 Mathematische Zeitschrift
Galois cohomology of special orthogonal groups. A. Wadsworth; R. Garibaldi; J. Tignol — 1997 Manuscripta mathematica
Fields of characteristic 2 with prescribed u-invariants. P. Mammone; J.-P. Tignol; A. Wadsworth — 1991 Mathematische Annalen