GARDNER, B. J. A Note on Radicals and Polynomial Rings. MATHEMATICA SCANDINAVICA, [S. l.], v. 31, p. 83–88, 1972. DOI: 10.7146/math.scand.a-11414. Disponível em: https://www.mscand.dk/article/view/11414. Acesso em: 29 apr. 2024.