1. Beidar K.I.: Rings with generalized identities. Moscow Univ. Math. Bull. 33, 53–58 (1978)
2. Beidar K.I., Bresar M., Chebotar M.A.: Functional identities with r-independent coefficients. Comm. Algebra 30(12), 5725–5755 (2002)
3. Beidar, K.I., Martindale, W.S. III., Mikhalev, V.: Rings with generalized identities. In: Pure and Applied Mathematics, Dekker, New York (1996)
4. Chuang C.L.: GPI’s having coefficients in Utumi quotient rings. Proc. Am. Math. Soc. 103(3), 723–728 (1988)
5. Chuang C.L., Lee T.K.: Rings with annihilator conditions on multilinear polynomials. Chin. J. Math. 24(2), 177–185 (1996)