Author: Vsesoi︠u︡znai︠a︡ konferent︠s︡ii︠a︡ po teorii i prilozhenii︠a︡m different︠s︡ialʹnykh uravneniĭ s otkloni︠a︡i︠u︡shchimsi︠a︡ argumentom 4th Kiev 1975