Vanishing of Hochschild cohomology for affine group schemes and rigidity of homomorphisms between algebraic groups. Margaux, Benedictus (2009) Documenta Mathematica
Variations on a theme of groups splitting by a quadratic extension and Grothendieck-Serre conjecture for group schemes F 4 with trivial g 3 invariant. Chernousov, V. (2010) Documenta Mathematica