AbdullayevF. G., SavchukV. V., SamoilenkoA. M., and SerdyukA. S. 2018. “International conference on the Mathematical Analysis, Differential Equations, and Their Applications (MADEA-8) devoted to the 80th Birthday of Academician A. M. Samoilenko”. Ukrains’kyi Matematychnyi Zhurnal 70 (10), 1439-40. https://umj.imath.kiev.ua/index.php/umj/article/view/1647.