GorbachukV. I. and GorbachukM. L. (1997) “Behavior of the extended spectral measure of a self-adjoint operator at infinity”, Ukrains’kyi Matematychnyi Zhurnal, 49(4), pp. 510–516. Available at: https://umj.imath.kiev.ua/index.php/umj/article/view/5024 (Accessed: 27July2024).