“Symmetrically-Spectral Operators on $\ell_p$ $(1\leq P< \infty)$ and $c_0$ Spaces”. Visnyk of V. N. Karazin Kharkiv National University. Ser. Mathematics, Applied Mathematics and Mechanics, no. 1081 (November 22, 2013): 33–44. Accessed October 24, 2026. https://periodicals.karazin.ua/mech_math/article/view/13127.