Dudkin, M. Y. (2002) “Analog of the Krein Formula for Resolvents of Normal Extensions of a Prenormal Operator”, Ukrains’kyi Matematychnyi Zhurnal, 54(4), pp. 555-562. Available at: https://umj.imath.kiev.ua/index.php/umj/article/view/4092 (Accessed: 16June2024).