Mogilevskii, V.I. (2015) “Characteristic matrices and spectral functions of first order symmetric systems with maximal deficiency index of the minimal relation”, Methods of Functional Analysis and Topology, 21(1), pp. 76–98. Available at: https://zen.imath.kiev.ua/index.php/mfat/article/view/602 (Accessed: 16 December 2025).