HÅVERSEN, S. Stability of pencils of cubic surfaces in $P^3$. MATHEMATICA SCANDINAVICA, [S. l.], v. 84, n. 1, p. 49–61, 1999. DOI: 10.7146/math.scand.a-13932. Disponível em: https://www.mscand.dk/article/view/13932. Acesso em: 5 may. 2024.