HARTNEY, J. F. T. On the Radical Theory of Distributively Generated Near-Ring. MATHEMATICA SCANDINAVICA, [S. l.], v. 23, p. 214–220, 1968. DOI: 10.7146/math.scand.a-10913. Disponível em: https://tidsskrift.dk/math/article/view/10913. Acesso em: 14 aug. 2026.