@misc{SchroederBruellPolonietal.2013, author = {Christian Schroeder and Tobias Bruell and Federico Poloni and Giacomo Sbrana}, title = {Enforcing solvability of a nonlinear matrix equation and estimation of multivariate ARMA time series}, institution = {Technische Universit{\"a}t Berlin}, type = {preprintmatheon}, year = {2013}, }