Romanyuk, A.S., Romanyuk, V.S., Savchuk, V.V., Samoilenko, A.M., Serdyuk, A.S. and Sokolenko, I.V. 2017. Oleksandr Ivanovych Stepanets’ (on his 75th birthday). Ukrains’kyi Matematychnyi Zhurnal. 69, 5 (May 2017), 579.