Mal'cev-Neumann rings and noncrossed product division algebras
  We first give a sufficient condition for a Mal'cev-Neumann ring of formal series to be a noncrossed product division algebra. This result is then used to give an elementary proof of the existence of noncrossed product division algebras (of degree 8 or degree p^2 for p any odd prime). 
C\'ecile Coyette
math.RA