Volodymyr Semenovych Korolyuk (the 80th anniversary of his birth) - Bratiichuk, N. S.; Gusak, D. V.; Kovalenko, I. N.; Portenko, N. I.; Samoilenko, A. M.; Skorokhod, A. V. (Ukrains’kyi Matematychnyi Zhurnal, 2005)