SAHANDI, Parviz; SHARIF, Tirdad. Dual of the Auslander-Bridger formula and GF-perfectness. Mathematica Scandinavica, Berkeley, CA, United States, v. 101, n. 1, p. 5–18, 2007. DOI: 10.7146/math.scand.a-15028. Disponível em: https://journals.msp.org/mscand/article/view/669. Acesso em: 24 jul. 2026.