HUNEKE, Craig; JORGENSEN, David A. Symmetry in the vanishing of Ext over Gorenstein rings. Mathematica Scandinavica, Berkeley, CA, United States, v. 93, n. 2, p. 161–184, 2003. DOI: 10.7146/math.scand.a-14418. Disponível em: https://journals.msp.org/mscand/article/view/801. Acesso em: 25 jul. 2026.