Duan , XuefengJiang , Zhuling and Liao , Anping. (2016). Low Rank Approximation Solution of a Class of Generalized Lyapunov Equation.
            <i>Journal of Computational Mathematics</i>. <i>34</i> (4).
            407-420.
         doi:10.4208/jcm.1601-m2015-0388