FRÖBERG, Ralf. An inequality for Hilbert series of graded algebras. MATHEMATICA SCANDINAVICA, [S. l.], v. 56, p. 117–144, 1985. DOI: 10.7146/math.scand.a-12092. Disponível em: https://tidsskrift.dk/math/article/view/12092. Acesso em: 14 aug. 2026.