MORTINI, R.; RUPP, R. Approximation by invertible elements and the generalized $E$-stable rank for $A({\boldsymbol D})_{\mathsf R}$ and $C({\boldsymbol D})_{\mathrm{sym}}$. MATHEMATICA SCANDINAVICA, [S. l.], v. 109, n. 1, p. 114–132, 2011. DOI: 10.7146/math.scand.a-15180. Disponível em: https://www.mscand.dk/article/view/15180. Acesso em: 1 may. 2024.