BOIJ, Mats. Gorenstein algebras with nonunimodal Betti numbers. Mathematica Scandinavica, Berkeley, CA, United States, v. 84, n. 2, p. 161–164, 1999. DOI: 10.7146/math.scand.a-13871. Disponível em: https://journals.msp.org/mscand/article/view/956. Acesso em: 25 jul. 2026.