[1]
R. V. Bozhok and V. D. Koshmanenko, “Singular Perturbations of Self-Adjoint Operators Associated with Rigged Hilbert Spaces”, Ukr. Mat. Zhurn., vol. 57, no. 5, pp. 622–632, May 2005, Accessed: Dec. 05, 2025. [Online]. Available: https://umj.imath.kiev.ua/index.php/umj/article/view/3628