1. D. I. Zaitsev, ?On the theory of minimax groups,? Ukr. Mat. Zh.,23, No. 5, 652?660 (1971).
2. D. I. Zaitsev, ?Groups satisfying the weak minimum condition,? Ukr. Mat. Zh.,20, No. 4, 472?482 (1968).
3. D. I. Zaitsev, ?Groups satisfying the weak minimum condition,? Mat. Sb.,78, No. 3, 323?331 (1969).
4. D. I. Zaitsev, ?Groups satisfying the weak minimum condition for non-Abelian subgroups,? Ukr. Mat. Zh.,23, No. 5, 661?665 (1971).
5. M. I. Kargapolov and Yu. I. Merzlyakov, Foundations of Group Theory [in Russian], Nauka, Moscow (1977).