1. Radicals of polynomial rings;Amitsur, S. A.;Canadian J. Math.,1956
2. Algebras over infinite fields;Amitsur, A. S.;Proc. Amer. Math. Soc.,1956
3. [Am73] — , Nil radicals. Historical notes and some new results, pp. 47-65 in Rings, Modules and Radicals (Proc. Colloq. Kesthely, 1971), North-Holland, 1973. MR0347873 (50 #374)
4. Radicals, tensor products, and algebraicity;Bergman, George M.,1989
5. Extensions of Rings and Modules