Babenko, V. F., N. V. Parfinovych, and D. S. Skorokhodov. “Optimal Recovery of Operator Sequences”. Matematychni Studii 56, no. 2 (December 26, 2021): 193-207. Accessed April 27, 2024. http://www.matstud.org.ua/ojs/index.php/matstud/article/view/257.