ILASH, N.B. Poincare series for the algebras of joint invariants and covariants of $n$ quadratic forms. Carpathian Mathematical Publications, [S. l.], v. 9, n. 1, p. 57–62, 2017. DOI: 10.15330/cmp.9.1.57-62. Disponível em: https://journals.pnu.edu.ua/index.php/cmp/article/view/1447. Acesso em: 6 may. 2024.