1. 1) H. Cartan, Théorie de Galois pour les corps non-commutatifs. Ann. de l'Ecole Norm. vol. 64 (1947). The author has not yet access to this paper and to a paper of J. Dieudonné cited in 4).
2. 2) R. Brauer, On a theorem of H. Cartan. Bull. Amer. Math. Soc. vol. 55 (1949). pp. 619-620.
3. 2) [Added in Proof] See also: L. K. Hua, Some properties of a sfield. Proc. Nat. Acad. Sci. vol. 35 (1949). pp. 533-537.
4. 3) M. Abe, Projective transformation groups over non commutative fields. Sijo Sugaku-Danwakai. 240 (1942). (in Japanese).
5. 4) J. Dieudonné, Les déterminants sur un corps non-commutatif. Bull. Soc. Math. de France vol. 71 (1943).