JENSEN, Chr. U. On Homological Dimensions of Rings with Countably Generated Ideals. Mathematica Scandinavica, Berkeley, CA, United States, v. 18, p. 97–105, 1966. DOI: 10.7146/math.scand.a-10784. Disponível em: https://journals.msp.org/mscand/article/view/2522. Acesso em: 25 jul. 2026.