Mortini, R. and Rupp, R. (2011) “Approximation by invertible elements and the generalized $E$-stable rank for $A({\boldsymbol D})_{\mathsf R}$ and $C({\boldsymbol D})_{\mathrm{sym}}$”, MATHEMATICA SCANDINAVICA, 109(1), pp. 114–132. doi: 10.7146/math.scand.a-15180.