[1]
V. Y. Slyusarchuk, “Equations in a Hilbert space whose solution sets are invariant with respect to a group isomorphic to a one-parameter group of unitary operators”,
Ukr. Mat. Zhurn., vol. 72, no. 1, pp. 86–99, Jan. 2020, Accessed: Apr. 07, 2025. [Online]. Available:
https://umj.imath.kiev.ua/index.php/umj/article/view/687