J. Dieudonné, Sur le socle d'un anneau simplex infinis,Bull. Soc. Math. France,70 (1942), pp. 46–75.
N. Jacobson, Structure of rings,Amer. Math. Soc. Colloquium Pub.,37, Providence, R. I., 1956.
N. Jacobson andC. E. Rickart, Jordan Homomorphisms of rings,69 (1950), pp. 479–502.