1. A. I. Abakumov, E. A. Palyutin, M. A. Taitslin, and Yu. E. Shishmarev, ?Categorical varieties,? Algebra Logika,11, No. 1, 3?38 (1972).
2. S. I. Adyan, ?Infinite irreducible systems of group identities,? Izv. Akad. Nauk SSSR, Ser. Mat.,13, No. 4, 715?734 (1970).
3. S. I. Adyan, ?Identity relations in groups,? in: International Congress of Mathematicians in Nice, 1970. Papers of Soviet Mathematicians [in Russian], Nauka, Moscow (1972), pp. 7?13.
4. S. I. Adyan, ?On certain torsion-free groups,? Izv. Akad. Nauk SSSR, Ser. Mat.,35, No. 3, 459?468 (1971).
5. S. I. Adyan, ?On subgroups of free periodic groups of odd exponent,? Tr. Mat. Inst. Akad. Nauk SSSR,112, No. 1, 64?72 (1971).