Romanyuk, A. S., Romanyuk, V. S., Savchuk, V. V., Samoilenko, A. M., Serdyuk, A. S., & Sokolenko, I. V. (2017). Oleksandr Ivanovych Stepanets’ (on his 75th birthday). Ukrains’kyi Matematychnyi Zhurnal, 69(5), 579. Retrieved from http://umj.imath.kiev.ua/index.php/umj/article/view/1718