Dudkin, M. E. “An Exact Inner Structure of the Block Jacobi-Type Unitary Matrices Connected With the Corresponding Direct and Inverse Spectral Problems”. Methods of Functional Analysis and Topology 14, no. 2 (June 25, 2008): 168–176. Accessed December 17, 2025. https://zen.imath.kiev.ua/index.php/mfat/article/view/380.