1. S. A. Amitsur e C. Procesi,Jacobson rings and Hilbert algebras with polynomial identities, Annali di Mat., (IV), v. LXXI, (1966), pp. 61–72.
2. I. N. Herstein,Topics in the theory of rings, Lecture Notes, Univ. of Chicago, 1965.
3. N. Jacobson,Structure of rings, Am. Math. Soc. Colloquim Publications, v. XXXVII, Seconda edizione (1964).
4. C. Procesi,Non-commutative affine rings, Atti Accad. Naz. Lincei, s. VIII, v. VIII, f. 6 (1967), pp. 239–255.
5. C. Procesi,Non commutative Jacobson rings, Annali Scuola Norm. Sup. Pisa, v. XXI, f. II, (1967), pp. 381–390.