Chapovsky, Yu. A. “On the Inverse Spectral Problem for a Commutative Field of Operator-Valued Jacobi Matrices”. Methods of Functional Analysis and Topology 8, no. 1 (March 25, 2002): 14–22. Accessed December 18, 2025. https://zen.imath.kiev.ua/index.php/mfat/article/view/172.