Weiping Shen, Chong Li and Xiaoqing Jin. (2016). An Ulm-Like Cayley Transform Method for Inverse Eigenvalue Problems with Multiple Eigenvalues.
            <i>Numerical Mathematics: Theory, Methods and Applications</i>. <i>9</i> (4).
            664-685.
         doi:10.4208/nmtma.2016.y15030