Borogovac,M. . “Reducibility of Self-Adjoint Linear Relations and Application to Generalized Nevanlinna Functions”. Ukrains’kyi Matematychnyi Zhurnal 74, no. 7 (August 9, 2022): 893–920. Accessed December 5, 2025. https://umj.imath.kiev.ua/index.php/umj/article/view/6084.