Amitsur S.A.: Identities in rings with involution. Israel J. Math. 7, 63–68 (1969)
Billig Y., Riley D., Tasic V.: Nonmatrix varieties and nil-generated algebras whose units satisfy a group identity. J. Algebra 190, 241–252 (1997)
Dooms A., Jespers E., Juriaans S.: On group identities for the unit group of algebras and semigroup algebras over an infinite field. J. Algebra 284, 273–283 (2009)
Giambruno A., Jespers E., Valenti A.: Group identities on units of rings. Arch. Math. 63, 291–296 (1994)
Giambruno A., Polcino Milies C., Sehgal S.K.: Group identities on symmetric units. J. Algebra 322, 2801–2815 (2009)
Giambruno A., Sehgal S.K., Valenti A.: Group algebras whose units satisfy a group identity. Proc. Amer. Math. Soc. 125, 629–634 (1997)
Giambruno A., Sehgal S.K., Valenti A.: Symmetric units and group identities. Manuscripta Math. 96, 443–461 (1998)
Giambruno A., Sehgal S.K., Valenti A.: Group identities on units of group algebras. J. Algebra 226, 488–504 (2000)
Gonçalves J. Z.: Free subgroups of units in group rings. Can. Math. Bull. 27, 309–312 (1984)
J. Z. Gonçalves and M. Shirvani, Free symmetric and unitary pairs in central simple algebras with involution, Contemp. Math., 2007, pp. 121–139.
Goodaire E.G., Jespers G., Polcino Milies C.: Alternative loop rings. North Holland, Amsterdam (1996)
Jespers E., Ruiz M.: On symmetric elements and symmetric units in group rings. Comm. Algebra 34, 727–736 (2006)
Liu C.-H.: Group algebras with units satisfying a group identity. Proc. Amer. Math. Soc. 127, 327–336 (1999)
Liu C.-H., Passman D.S.: Group algebras with units satisfying a group identity. II. Proc. Amer. Math. Soc. 127, 337–341 (1999)
Passman D.S.: The algebraic structure of group rings. John Wiley, New York (1977)
Passman D.S.: Group Algebras whose units satisfy a group identity II. Proc. Amer. Math. Soc. 125, 657–662 (1997)