JAMBOR, Paul E. Radical of splitting ring extensions. Mathematica Scandinavica, Berkeley, CA, United States, v. 65, p. 50–58, 1989. DOI: 10.7146/math.scand.a-12264. Disponível em: https://journals.msp.org/mscand/article/view/1386. Acesso em: 24 jul. 2026.