International conference on the mathematical analysis, differential equations, and their applications (MADEA-8) devoted to the 80th birthday of Academician A. M. Samoilenko - Abdullayev, F. G.; Savchuk, V. V.; Samoilenko, A. M.; Serdyuk, A. S. (Ukrains’kyi Matematychnyi Zhurnal, 2018)