1. V. Chernousov, Variations on a theme of groups splitting by a quadratic extension and Grothendieck–Serre conjecture for group schemes F 4 $F_{4}$ with trivial g 3 $g_{3}$ invariant, Doc. Math. Extra volume: Andrei A. Suslin sixtieth birthday (2010), 147–169.
2. J.-L. Colliot-Thélène and M. Ojanguren, Espaces principaux homogènes localement triviaux, Publ. Math. IHÉS, 75 (1992), 97–122.
3. J.-L. Colliot-Thélène and J.-J. Sansuc, Principal homogeneous spaces under flasque tori: Applications, J. Algebra, 106 (1987), 148–205.
4. Lecture Notes in Mathematics;M. Demazure,1970
5. R. Fedorov, Affine Grassmannians of group schemes and exotic principal bundles over affine lines, ArXiv e-prints 1308.3078 (2013).