HARTNEY, J. F. T. On the Radical Theory of Distributively Generated Near-Ring. Mathematica Scandinavica, Berkeley, CA, United States, v. 23, p. 214–220, 1968. DOI: 10.7146/math.scand.a-10913. Disponível em: https://journals.msp.org/mscand/article/view/2440. Acesso em: 25 jul. 2026.