Gorbachuk, M. L., A. Y. Luchka, Y. A. Mitropolskiy, and A. M. Samoilenko. “Yurii Dmitrievich Sokolov (on His 100th Birthday)”. Ukrains’kyi Matematychnyi Zhurnal, Vol. 48, no. 11, Nov. 1996, pp. 1443-5, https://umj.imath.kiev.ua/index.php/umj/article/view/5196.