1. V. A. Andrunakievich, "Radicals of associative rings, I," Mat. Sb.,44(86, No. 2, 179–212 (1958).
2. K. A. Zhevlakov, "The lower nil radical of alternative rings," Algebra Logika,6, No. 4, 11–17 (1967).
3. A. G. Kurosh, "Radicals of rings and algebras," Mat. Sb.,33(75, No. 1, 13–26 (1953).
4. A. S. Markovichev, "Rings of type (γ, δ)," in: Fourteenth All-Union Algebra Conference (Abstracts of Reports), Vol. 2, Novosibirsk (1977).
5. A. S. Markovichev, "On the heredity of radicals of rings of type (γ, δ)," Algebra Logika,17, No. 1, 33–55 (1978).