[1]
V. L. Ostrovskii and Y. S. Samoilenko, “On pairs of unbounded self-adjoint operators satisfying an algebraic relation”, Ukr. Mat. Zhurn., vol. 45, no. 9, pp. 1253–1258, Sep. 1993, Accessed: Dec. 05, 2025. [Online]. Available: https://umj.imath.kiev.ua/index.php/umj/article/view/5927