1. I. N. Balaba, “Rings of quotients of semiprime graded rings,” in: Works Int. Sem. “Universal Algebra and Its Applications [in Russian], Volgograd (2000), pp. 21–28.
2. I. N. Balaba, A. L. Kanunnikov, and A. V. Mikhalev, “Graded quotient ring of associative rings. I,” Fundam. Prikl. Mat., 17, No. 2, 3–74 (2011/2012).
3. K. I. Beidar, “Rings of quotients of semiprime rings,” Mosc. Univ. Math. Bull., 33, No. 5, 29–34 (1978).
4. K. I. Beidar,W. S. Martindale, and A. V. Mikhalev, Rings with Generalized Identities, Marcel Dekker, New York (1995).
5. K. I. Beidar and A. V. Mikhalev, “Orthogonal completeness and algebraic systems,” Russ. Math. Surv., 40, No. 6, 51–95 (1985).