[2] A. P.  Kemer: 
Finite basing of the identities of the associative algebras. Algebra i logika 26 (1987), 597–641. (Russian) 
DOI 10.1007/BF01978692 | 
MR 0985840 
[3] V. V.  Schigolev: 
Examples of infinitely based $T$-spaces. Matem. sb. 191 (2000), 143–160. (Russian) 
MR 1773258 
[4] A. I.  Belov: 
Counterexamples to the Specht’s problem. Matem. sb. 191 (2000), 13–24. (Russian) 
MR 1773251 
[5] N. I.  Sandu: 
Infinite independent systems of the identities of the associative algebras over an infinite field of characteristic 2. Matem. zametki 74 (2003), 603–611. (Russian) 
MR 2042973 
[6] The Dnestr Notebook. Unsolved Problems of the Ring and Module Theory. Institute of Mathematics of SD AS USSS, Novosibirsk, 1982. (Russian)
[7] A. E.  Zalesskij and A. V.  Mikhalev: 
Group rings. The results of science and technique. Modern Mathematics Problems. Main Directions, VINITI, Moskva, 1973, pp. 5–118. (Russian) 
MR 0414623 
[9] S.  Leng: 
Algebra. Addison-Wesley Publishing Company, Reading, 1965. 
MR 0197234 
[10] W.  Magnus, A.  Karrass and D.  Solitar: Combinatorial Group Theory. Wiley, New York, 1966.