Babenko, V. F., Ligun, A. A., & Motornyi, V. P. (2000). On the results of N. P. Korneichuk obtained in 1990–1999. Ukrains’kyi Matematychnyi Zhurnal, 52(1), 5-8. https://umj.imath.kiev.ua/index.php/umj/article/view/4391